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Steel Structure Damage Analysis Textbook Version: 13.3 © 2011 - 2013 Inter-Industry Conference on Auto Collision Repiar DAM12-STMAN1-E

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Page 1: DamageAnalysis SteelStructure Textbook

Steel�StructureDamage�Analysis

Textbook

Version:�13.3

©�2011�-�2013�Inter-Industry�Conference�on�Auto�Collision�Repiar

DAM12-STMAN1-E

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Steel�Structure�Damage�AnalysisTextbook

Table�of�Contents 3

Contents

Introduction..............................................................................................................................7Obligations�To�The�Customer�And�Liability.......................................................................... 7

Module�1�-�Vehicle�Structures................................................................................................13Types�Of�Vehicle�Construction........................................................................................... 13The�Collision...................................................................................................................... 15Analyzing�Vehicle�Damage................................................................................................ 18Analyzing�Vehicle�Damage�(con't)..................................................................................... 20Measuring�For�Damage�Analysis.........................................................................................25Module�Wrap-Up............................................................................................................... 33

Module�2�-�Structural�Damage�Analysis.................................................................................37General�Repair�Considerations........................................................................................... 37Front� Impact....................................................................................................................... 46Side�Impact�Damage�Analysis............................................................................................ 52Rear�Impact�Damage�Analysis............................................................................................ 63Stationary�Glass.................................................................................................................. 66Body-Over-Frame�Vehicles..................................................................................................70Module�Wrap-Up............................................................................................................... 73

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Introduction

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IntroductionTextbook

Steel�Structure�Damage�Analysis 7

Obligations�To�The�Customer�And�Liability

The�Collision�Repair�Industry�hasan�obligation�to�correctly�repair�thecustomer’s�vehicle.�Collision�repairs�mustbe�performed�using:

• recommended�or�testedprocedures�from�vehicle�makers,I-CAR,�and�other�research�andtesting�organizations.

• quality�replacement�parts�andmaterials.

• repair�processes�and�parts�aswritten�and�agreed�upon�in�therepair�order.

• If�items�on�the�repair�agreementare�not�consistent�with�the�repairorder,�it�can�be�considered�fraud.

Performing�proper�collision�repairsrequires�using�parts�and�procedures�thatkeep�remaining�warranties�intact.

Collision�repairs�must�restore:

• safety.• structural�integrity.• durability.• performance.

• fit.• finish.

Throughout�the�damage�analysis�andrepair�process�the�repairer�and�insurermust:

• communicate�with�each�other.• maintain�constant�communicationwith�the�customer.

• be�in�agreement�with�each�otherand�the�customer�on�how�repairswill�be�performed.

• inform�the�customer�of�anychanges�in�the�repair�plan�fromthe�original�repair�agreement,�andexplain�the�changes�and�why�theyhave�to�be�made.

To�reduce�liability:

• make�sure�that�all�repairs�areperformed�thoroughly,�correctlyand�as�listed�in�the�damage�report.

• follow�proper�procedures.• use�quality�replacement�parts�andmaterials.

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Steel�Structure�Damage�Analysis 8

• have�documentation�of�requiredrepairs�with�detailed�recordkeeping�available�for�customers.Technicians�are�considered�theexperts�and�are�expected�to�beknowledgeable�on�how�to�performa�quality�repair.

Keeping�thorough�records�includes�morethan�recording�the�date,�mileage,�andpre-existing�damage.�Record�keepingalso�includes:�making�sure�all�notes�arelegible.

• verifying�the�repairs�that�weremade�or�not�made.

• having�the�customer�sign�awaiver�for�repairs�that�they�donot�want�performed.�Repairersmust�determine�their�liability�onnot�repairing�safety�systems�suchas�restraint�and�anti-lock�brakesystems.

• keeping�computer�printouts�orworksheets�on�file�showing�wheelalignment�readings�or�vehicledimensions�before�and�afterrepairs.

• keeping�scan�tool�printouts�andrecords�of�computer�codes�forairbag,�anti-lock�brake,�emission,and�powertrain�control�module(PCM)�systems.�attaching�the�OEMor�other�tested�procedure�printoutto�the�vehicle�repair�order.

• keeping�receipts�for�all�subletwork�performed.

Liability�insurance�that�covers�the�repairfacility�may�not�always�cover�all�damages.For�example:

• the�policy�may�not�coverfaulty�repairs,�leaving�liabilityresponsibility�completely�on�thefacility.

• a�shop�owner�may�find�that�repairfacility�liability�coverage�may�notcover�the�full�amount�awarded�ina�lawsuit.�The�shop�owner�wouldhave�to�pay�the�difference.

It�is�difficult�to�reduce�the�risk�of�liabilityexposure.�The�part�that�the�repairer�cancontrol�is�the�chance�of�being�found�atfault.�Chances�can�be�minimized�by:• using�recommended�or�tested�procedures�from�the�vehicle�makers,�I�CAR,�orother�research�and�testing�organizations.

• using�quality�replacement�parts�and�materials�that�restore�fit,�finish,�durability,and�perform�at�least�as�well�as�the�original.

• keeping�thorough�records.

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Steel�Structure�Damage�Analysis 9

Keeping�thorough�records�includes�morethan�recording�the�date,�mileage,�and�pre-existing�damage.�Record�keeping�alsoincludes:• making�sure�all�notes�are�legible.• verifying�the�repairs�that�were�made�or�not�made.• having�the�customer�sign�a�waiver�for�repairs�that�they�do�not�want�performed.Repairers�must�determine�their�liability�on�not�repairing�safety�systems�such�asrestraint�and�anti-lock�brake�systems.

• keeping�computer�printouts�or�worksheets�on�file�showing�wheel�alignmentreadings�or�vehicle�dimensions�before�and�after�repairs.

• keeping�scan�tool�printouts�and�records�of�computer�codes�for�airbag,�anti-lockbrake,�emission,�and�powertrain�control�module�(PCM)�systems.

• attaching�the�OEM�or�other�tested�procedure�printout�to�the�vehicle�repair�order.• keeping�receipts�for�all�sublet�work�performed.

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Module�1�-�VehicleStructures

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Steel�Structure�Damage�Analysis 13

Types�Of�Vehicle�Construction

Learning�objectives�for�this�moduleinclude:

• identifying�the�different�types�ofvehicle�designs.

• explaining�how�unitized�structuresare�designed�to�collapse.

• identifying�how�different�impactangles�transfer�collision�energyand�create�different�types�ofdamage.

• reading�vehicle�measurements�todetermine�structural�damage.

Jaguar�XF

This�Jaguar�XF�unibody�shows�the�inner�structurewith�the�outer�panels�and�trim�removed.

A�unibody�structure:

• has�a�single�structure�built�byattaching�multiple�parts�of�sheetmetal.�Attachment�methodsinclude�spot�welds,�laser�welds,rivets,�adhesives,�or�a�combinationof�methods.

• has�exterior�welded-on�bodypanels,�such�as�roofs�and�quarterpanels,�included�in�the�overallstructure.

• is�built�with�the�drivetrain,steering,�and�suspension�partsmounted�directly�to�the�bodystructure.

• depends�on�correct�structuralalignment�for�proper�steering�andsuspension�alignment.

• is�commonly�used�for�mostcars,�an�increasing�number�ofsport-utility�vehicles�(SUVs),�andsome�trucks,�such�as�the�HondaRidgeline.

Audi�R8

This�is�the�space�frame�for�an�Audi�R8.

Space�frame�vehicles:

• are�similar�to�the�unibodystructure.

• are�unitized�structures�withattached�outer�body�panels.

• like�unibody�structures,�havethe�drivetrain�and�steering�andsuspension�mounted�to�the�bodystructure.

• like�unibody�structures,�may�havethe�outer�panels�attached�withadhesives,�fasteners,�welds,�or�acombination�of�these�attachmentmethods.

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Steel�Structure�Damage�Analysis 14

The�primary�difference�between�spaceframes�and�unibody�structures�is�thatspace�frames�are:

• lighter�weight,�either�made�fromlightweight�metal�or�a�metal�andcomposite�structure�combination.

• less�dependent�on�outer�bodypanels�for�strength.

• similar�to�the�inner�structurecommon�on�race�car�designs.

Ford�F-150

A�body-over-frame�vehicle�has�a�separate�unitizedstructure�that�is�bolted�to�the�frame.

Body-over-frame�vehicles:

• have�a�frame�independent�of�theunitized�structure.�Two�main�typesof�frames�include�perimeter�andladder�designs.�Ladder�frames�aremore�common�on�recreationalvehicles�(RVs),�busses,�andcommercial�trucks.

• have�a�separate�unitized�structurebolted�to�the�frame.�It�usesthe�same�energy�managementcharacteristics�that�are�used�forunibody�vehicles.

• have�the�engine,�drivetrain,�andsteering�and�suspension�partsbolted�to�the�frame.

• may�be�called�full-frame�vehicles.

Body-over-frame�designs�in�non-commercial�applications�are�used�forpickup�trucks�and�many�SUVs,�vehiclesprimarily�used�for�heavy-duty�purposes.

Frames�are�either�C-channel-type�styles�(left)�or�box-type�(right).

Modern�pickup�truck�and�SUV�framedesigns�vary�depending�on�the�vehicle.Features�of�modern�frame�designsinclude:

• a�combination�of�characteristicsfrom�both�ladder-type�andperimeter-type�frame�designs.

• both�open�C-channel�and�box-type�rails.

• hydroformed�rails.�Box-type�andtubular�hydroformed�rails�areflangeless,�one-piece�structuresformed�from�a�metal�tube.�Moreinformation�on�hydroformed�partswill�be�discussed�later�in�thecourse.

• welded�or�riveted�mountingbrackets.

• crossmembers�that�are�welded�orriveted�to�the�frame.

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Steel�Structure�Damage�Analysis 15

• collapse�zones.• torque�boxes.

Many�pickup�trucks�and�SUVs�havemodern�frames�with�a�lower�center�ofgravity�for�better�handling�and�a�more�car-like�ride.

The�Collision

A�thorough�damage�analysis�may�require�some�partremoval�to�accurately�assess�damage.

During�damage�analysis,�the�estimator�/appraiser�must:

• determine�how�to�ensure�acomplete�and�safe�repair,�ensuringthat�the�collision�characteristicsare�restored.

• ensure�that�the�damage�reportis�written�so�that�the�vehiclestructure�is�restored�to�pre-accident�integrity.�This�willmake�sure�the�structure�reacts�asdesigned�by�the�vehicle�maker�in�asubsequent�collision.

Using�specific�materials�and�part�design,automotive�engineers�have�designedthe�vehicle�to�collapse�in�a�predictablemanner�to�protect�those�inside�the

passenger�compartment.�Changing�a�partdesign�or�repairing�parts�that�should�notbe�repaired�can�affect�the�original�design,which�can�alter�the�collision�energymanagement�of�the�vehicle.

It�is�important�to�note�that�the�repairerand�/�or�insurer�may�be�liable�for�anypersonal�injury�or�property�damagecaused�by�improper�repairs.

Basic�vehicle�design�divides�the�unitized�body�orframe�into�three�sections.

To�determine�how�the�vehicle�is�repaired,it�is�helpful�to�understand�how�the�vehicleis�constructed.�Each�vehicle�is�designedwith�three�distinct�sections:

• front.• rear.• center.

Each�section�has�a�specific�function�in�theevent�of�a�collision.�The�front�and�rearstructure�is�designed�to:

• collapse�up�to�a�specific�point.• transfer�energy�to�the�opposite�endof�the�vehicle.

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Steel�Structure�Damage�Analysis 16

This�“controlled�deceleration”�of�thevehicle�helps�absorb�collision�energyas�well�as�re-route�the�collision�energyaround�the�center�section.

Toyota�Venza

Late�model�vehicle�structures�have�increased�thestrength�of�the�side�structures�to�limit�intrusion�intothe�passenger�compartment.

Unlike�the�front�and�rear�sections�of�thevehicle,�the�center�section�(or�passengercompartment):

• is�not�designed�to�collapse.• has�collision�energy�transferredaround�it.

• remains�intact�and�provides�a�safespace�for�the�vehicle�occupants.

• keeps�occupants�inside�the�vehicleduring�a�collision.

The�left�and�right�front�rails�and�bumperreinforcement�have�absorbed�collision�energy�fromthis�offset�impact.

Collision�energy�starts�at�the�point�ofimpact�on�the�vehicle.�The�absorption�andtransfer�of�collision�energy�is�done�using:�

• crush�zones,�which�are�specificdesigns�in�the�steel�used�tocollapse�or�bend�a�part�in�acontrolled�manner.�These�areasabsorb�the�collision�energy.��

• different�strengths�of�steel,�whichmay�be�used�to�either�absorb�ortransfer�the�collision�energy.��

• different�thicknesses�of�steel.�Steelthickness�can�vary�within�a�partdepending�on�design.��

• reinforcements.�Reinforcementsare�used�to�transfer�collisionenergy�to�other�areas�of�thevehicle.

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Ford�Fusion

Vehicle�makers�use�crush�boxes�and�tailor-weldedparts�to�absorb�collision�energy.

Crush�zones�are�designed�into�the�vehicleto�absorb�collision�energy.�Crush�zonesmay�be:

• holes,�dimples,�or�slots�stampedinto�a�part.

• made�by�using�tailor-weldedblanks,�tailor-rolled�blanks,�and�/or�reinforcements.

• different�types�of�steel�strength�andthicknesses.

• formed�ribs�or�stamped�areasacross�the�width�of�the�part.�Thesemay�also�be�called�convolutions.

• kick-up�or�offset�areas.�Theseare�designed�to�bend�during�acollision�and�redirect�collisionenergy�in�certain�ways.�A�kick-upor�offset�area�may�be�designed�todirect�the�engine�and�transmissionunder�the�passenger�compartment,rather�than�into�it,�during�acollision.

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Refer�to,�"Video:�Understanding�CollisionForces"�in�the�presentation�for�a�videoon�how�collision�energy�managementdesigns�have�advanced�over�the�pastseveral�decades.

Analyzing�Vehicle�Damage

Audi�Q5

Direct�damage�to�this�vehicle�occurred�at�thepassenger-side�front�rail.

When�analyzing�vehicle�damage,�it�ishelpful�to�determine�the�area�of�directdamage.�Direct�damage:

• is�the�point�of�impact.• is�the�area�of�the�vehicle�that�hasthe�most�obvious�damage.

• is�generally�the�point�wheredamage�analysis�begins.

• may�also�be�referred�to�as�primarydamage�or�initial�impact.

The�inertial�damage�will�vary�depending�on�thecollision�energy.�For�example,�vehicles�involved�in�afront�impact�will�have�inertial�damage�from�parts�andobjects�moving�forward.

Mass�inertia�damage�is�caused�byunrestrained�objects�in�the�vehicle,�orparts�of�the�vehicle�itself,�that�continuemomentum�after�the�vehicle�has�beenstopped�by�a�collision.�This�can�damageboth�the�interior�and�exterior�of�thevehicle.

An�example�of�mass�inertia�is�a�trainengine�with�several�boxcars�attached.When�the�engine�brakes,�the�first�boxcarbehind�the�engine�wants�to�continue�itsforward�motion�as�well�as�all�the�otherboxcars.

Chevrolet�Malibu

The�dent�in�this�quarter�panel�is�caused�by�stressfrom�the�damaged�structure.

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Indirect�damage�is�essentially�the�same�asmass�inertia�damage.�Indirect�damage:

• is�caused�by�the�force�of�thecollision�as�it�moves�through�thevehicle.

• occurs�away�from�the�point�ofimpact.

• can�be�found�anywhere�on�thevehicle,�which�makes�it�difficult�tolocate.

• may�not�be�evident�without�closeinspection.

• may�be�identified�by�accuratemeasuring.

• can�include�mechanical�parts�suchas�wheel�bearing�damage�causedby�an�impact�to�a�wheel.�Bentengine�mount�brackets�may�alsobe�considered�a�type�of�indirectdamage.

• can�include�electrical�andelectronic�parts.�Examplesinclude�shorted�wires�or�damageto�electronic�parts�caused�bycollision�forces.

What�are�some�types�of�damage�that�canbe�caused�by�collision�inertia?

Motor�mounts�can�be�damaged�from�the�enginemoving�forward�or�rearward�during�impact�(left).Items�in�a�pickup�truck�bed�can�cause�damage�to�thefront�of�the�box�or�the�tailgate�(right).

Types�of�damage�that�can�be�caused�bymass�inertia�include:

• damaged�pickup�bed�or�trunk�fromunrestrained�items.

• motor�mount�damage�from�a�frontor�rear�impact.

• cracked�composite�radiator�coresupport�from�a�rear�impact.

• collapsed�steering�column�fromthe�driver�impacting�the�steeringwheel.

• damage�to�seat�frames,�centerconsoles,�and�door�trim�panels.

• windshield�cracks.

Cadillac�DTS

The�uneven�gap�between�the�quarter�panel�and�dooris�an�indication�of�indirect�damage�on�this�vehicle.

Indirect�damage�today�looks�differentfrom�indirect�damage�on�older�modelvehicles.�Stronger�steels�transfer�morecollision�energy�around�the�passengercompartment.�There�may�be�no�visiblepanel�gap�misalignment,�but�still�beindirect�damage�away�from�the�directimpact�area.�Measuring�may�be�the�onlyway�to�verify�indirect�damage�due�tocollision�energy�transfer.

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A�buckle�in�the�roof�used�to�be�a�verycommon�indicator�of�structural�damage,but�this�is�no�longer�the�case.�The�solidstructure�of�the�center�section�oftenprevents�this�from�happening,�however,collision�energy�still�may�have�radiatedto�the�opposite�end�of�the�vehicle.�Newbody�designs�change�the�way�a�vehicle�isinspected.

Primary�damage�to�this�vehicle�is�the�direct�impactto�the�door�(left),�however,�the�bumper�cover�(right)also�took�an�impact�during�the�same�collision.�Thistype�of�damage�is�considered�secondary.

Secondary�damage:

• is�damage�that�resulted�away�fromthe�initial�impact,�during�a�secondimpact�with�another�object.

• includes�direct�and�indirectdamage.

Depending�on�the�collision,�there�maybe�multiple�locations�of�damage�thatis�secondary�damage.�For�example,�avehicle�may�hit�a�barrier,�spin,�and�hitanother�barrier�or�oncoming�vehicle.This�can�present�unique�challenges�whentrying�to�determine�the�point�of�initialimpact�since�there�may�be�several�areasthat�show�direct�damage.�Customer

interviews�can�be�helpful�in�determininghow�a�collision�occurred.

Analyzing�Vehicle�Damage�(con't)

This�is�an�example�of�an�offset�collision.�(Courtesy�ofVolvo�Cars�North�America,�LLC)

Types�of�impact�angles�include:

• straight�on,�front�or�rear.• offset,�which�is�just�a�portion�ofthe�front�or�rear�of�the�vehicle.

• rollover.• side.

Another�type�of�impact�angle�is�when�anobject�directly�hits�the�underbody.�This�isnot�as�evident,�as�most�of�the�damage�willbe�underneath�the�vehicle.

This�is�an�example�of�an�offset�collision�and�astraight-on�side�impact�collision.

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Determining�the�direction�of�the�impactis�helpful�for�a�thorough�analysis.Understanding�how�energy�traveledthrough�the�vehicle�structure:

• helps�the�appraiser�/�estimatoridentify�likely�secondary�orindirect�damage.�It�is�necessary�tolook�for�where�the�damage�wasinitiated,�then�try�and�follow�thepath�the�energy�likely�traveledthrough�the�vehicle.

• starts�by�examining�the�impactangle.�Each�impact�angle�canaffect�how�damage�is�transferredinto�the�vehicle�structure.�Forexample,�a�side�impact,�due�tothe�very�strong�side�structure,may�result�in�the�front�andrear�swaying�to�the�side�of�thecollision,�giving�the�vehicle�abanana�shape.�With�late�modelvehicles,�a�banana�shape�generallyrequires�severe�impact�forces�dueto�the�reinforcement�of�the�centersection.

Another�example�is�when�a�vehicle�hasan�offset�front-end�collision.�This�typeof�damage�may�cause�the�front�end�tosway�toward�one�side�of�the�vehicle.Depending�on�the�speed�of�the�collision,the�energy�can�be�diverted�to�the�rear�ofthe�vehicle,�causing�height�problems�inthe�rear�section,�or�having�it�swayed�toone�side�or�the�other.

Refer�to�the�"Activity:�Impact�AnglesAnd�Damage�Analysis"�for�an�activity�ondetermining�the�impact�angle.

This�particular�damage�shows�mash,�twist,�andpossibly�diamond.

Collision�impacts�result�in�specificdamage�conditions�to�the�vehiclestructure.�The�extent�or�number�ofconditions�created�in�the�vehicle�structuredepends�on�the�angle�and�severity�of�thecollision.

Types�of�damage�conditions�include:

• diamond.• twist.• sag.• mash.• side�sway.

A�diamond�condition�is�when�one�side�of�the�vehicleis�pushed�forward�or�rearward�of�the�opposite�side.

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The�diamond�condition:

• is�often�created�by�an�offsetcollision�impact�where�one�sideof�the�vehicle�is�moved�forward�orrearward�of�the�opposite�side.

• causes�the�center�section�to�be�outof�square,�taking�on�a�diamond-like�appearance.

• is�commonly�associated�with�full-frame�vehicles.

• is�starting�to�be�found�on�unibodyvehicles�as�increased�use�ofreinforcements�and�ultra-high-strength�steel�(UHSS)�becomestandard�in�vehicle�construction.For�example,�diamond�may�occurfrom�a�direct�impact�to�the�rockerpanel.�If�there�is�diamond�in�aunibody�vehicle,�it�is�generallyaccompanied�by�a�dent�or�wrinklein�the�floor�pan.

Twist�occurs�when�a�portion�of�the�center�section�ishigher�than�the�other.

Twist:

• occurs�when�the�center�section�ofa�vehicle�is�out�of�level.�Either�one

or�both�ends�are�out�of�level�witheach�other.

• is�a�height�problem,�where�aportion�of�the�vehicle�centersection�is�higher�or�lower�than�theopposite�side.

• may�not�be�evident�in�theupperbody�structure,�however,the�vehicle�may�appear�as�thoughthere�is�suspension�damage.�Onfull-frame�vehicles,�twists�canoccur�in�the�frame�and�/�or�theunitized�structure.

• can�occur�from�colliding�witha�curb�or�ditch�at�high�speed,becoming�airborne�at�one�point,or�being�involved�in�a�rear�impact.

It�is�important�for�technicians�to�repair�thetwist�condition�before�it�is�anchored�forpulling.�Not�making�this�repair�ahead�oftime�can�lock�the�twist�condition�into�thevehicle.

Sag�occurs�when�there�are�height�problems�with�thefront�or�rear�of�the�vehicle.

Sag�is:

• a�condition�where�the�front�or�rearsections�of�the�vehicle�or�the�cowl

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have�height�measurements�that�areout�of�specification.

• generally�the�result�of�a�straight-oncollision.

• indicated�by�body�panels�havinginconsistent�panel�gaps�from�topto�bottom,�generally�tighter�at�thetop�and�wider�at�the�bottom.�Thishappens�when�the�cowl�dropsdown�in�a�front-end�collision.

Due�to�the�stronger�center�sections,�thiscondition�is�not�as�common�as�it�was�onolder�models.

Mash�occurs�when�the�frame�has�collapsed�fromcollision�forces.

Mash�is:

• also�called�collapse�or�short�rail.• a�condition�where�any�sectionor�frame�member�is�shorter�thanfactory�specification.

• common�on�front�and�rear�railsfrom�front�and�rear�impacts.Damage�may�be�more�visible�inthe�front�and�rear�section�of�thevehicle�compared�to�the�centersection.�For�example,�collapse�ofthe�rails�may�lead�to�distortions�or

buckles�in�panels�such�as�fenders,hoods,�and�quarter�panels.

Side�sway�occurs�when�the�front�or�rear�of�thevehicle�is�pushed�to�one�side.

Sway,�or�side�sway:

• occurs�when�collision�energyforces�a�part�of�the�vehicle�to�oneside�or�the�other.

• is�a�width�misalignment.• generally�occurs�to�the�front�orrear�section�of�the�vehicle.

• may�be�evident�by�wide�gaps�onone�side�of�the�vehicle�and�narrowgaps�on�the�opposite�side.�Directimpact�would�generally�take�placeon�the�side�of�the�vehicle.

When�analyzing�damage,�an�indication�ofside�sway�is�evidence�of�buckling�on�theinside�of�the�driver�side�rail�and�bucklingon�the�outside�of�the�passenger�side�rail.

Refer�to�the�"Activity:�Determine�TheDamage�Contidtion"�for�an�activity�ondeterming�the�damage�condition.

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Checking�wheel�positioning�can�determine�if�there�isdamage�to�the�suspension�or�vehicle�underbody.

Additional�damage�indicators�commonlyassociated�with�the�damage�conditionsinclude:

• the�position�of�the�wheel�inthe�wheelhouse.�The�mostobvious�assumption�is�that�thereis�suspension�damage.�However,if�this�is�not�visible,�it�is�likely�thatthere�is�damage�to�the�suspensionmounting�areas�that�are�part�of�thevehicle�structure.

• cracked�seam�sealers�or�paint.�Thismay�require�lifting�the�carpetingor�raising�the�vehicle�to�view�thefloor�pan�or�trunk�floor.�Crackedseam�sealer�may�be�an�indicationof�inner�structure�damage.

• improper�closure�panel�operation.If�the�door,�hood,�or�deck�lidbinds,�drops,�or�sticks�whenopening,�it�may�be�an�indicationof�larger�structural�damage.

• a�cracked�windshield.�Thisparticular�damage�is�an�indicatorthat�there�is�stress�in�theupperbody�structure�that�causedthe�glass�to�crack.

• buckled�exterior�panels.�Whiledented�panels�are�often�a�result

of�a�direct�impact,�structuremisalignment�will�also�causepanels�to�buckle.

This�estimator�is�checking�for�visual�indicators�ofmore�extensive�structural�damage.

When�looking�at�visual�clues�regardingstructural�damage,�note�that:

• these�should�only�be�used�asguides.

• they�should�never�be�used�asthe�only�method�to�determinestructural�damage.�However,they�can�be�used�as�evidencethat�structural�three-dimensionalmeasuring�must�be�done.

• in�most�instances,�measuring�maybe�the�only�practical�method�todetermine�if�structural�damageexists.�The�visual�indicators�simplyshow�that�the�vehicle�should�bemeasured.

Most�estimators�and�auto�physical�damageappraisers�use�visual�clues�to�identifyif�measuring�is�required.�It�is�rare�to�dofield�measurements.�Most�structuralmisalignment�problems�are�generally

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evident.�However,�there�are�situationswhen�damage�is�very�subtle,�and�onlymeasuring�will�identify�a�structuralproblem.

Measuring�For�Damage�Analysis

Three-dimensional�measuring�systems,�such�as�thisone,�can�be�used�to�measure�without�anchoring�to�abench.

Measuring�for�damage�analysis�helps:

• locate�indirect�damage.�Knowingthat�damage�in�unitized�and�full-frame�structures�radiates�beyondthe�area�of�initial�impact,�meansthat�locating�the�indirect�damageis�critical�in�ensuring�an�accurateestimate.

• locate�hidden�damage.�Hiddendamage�is�structural�damage�thatmay�not�be�evident,�as�exteriorpanels�and�trim�often�hide�bendsand�kinks�in�the�structure.

• determine�a�repair�plan.�The�repairplan�allows�the�technician�todetermine�what�precisely�mustbe�done�to�restore�vehicle�safety,performance,�and�appearance.

• identify�suspension�damage.

The�estimate,�or�damage�report,�isgenerally�not�considered�complete�until�acomplete�and�thorough�damage�analysisis�done�that�includes�measuring�thevehicle�structure.

When�making�measurements�or�lookingat�measuring�results,�compare�themeasurements�with�the�visual�damage.Try�and�determine�if�the�measurementsmatch�the�appearance�of�the�vehicle�andthe�direction�of�impact.�Try�to�determinehow�far�the�damage�radiates�into�thevehicle.�In�other�words,�measure�untilmeasurements�are�found�within�normaltolerance.

Crosscheck�point-to-point�measurements�can�beused�to�determine�movement�in�the�upperbodystructure.

Types�of�measurements�used�for�vehiclerepair�include:

• point-to-point.�Point-to-pointmeasurements�are�used�fordamage�analysis�only,�and�are�nota�substitute�for�three-dimensionalmeasuring.

• three-dimensional�measuring.�Thistype�of�measuring�is�required�forany�type�of�structural�repair�and

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can�be�used�for�damage�analysisas�well.

Tape�measures�and�tram�gauges�are�used�to�makepoint-to-point�measurements.

Point-to-point�measurements�can�be�takenwith�a:

• tape�measure.• tram�gauge.

Tape�measures�must:

• have�a�metric�scale,�since�mostdimension�sheets�list�dimensionsin�metric�measurements.

• lay�flat�between�the�points�beingmeasured.�Bends�or�twists�willgive�inaccurate�readings.

A�tram�gauge:

• is�a�telescoping�measuring�devicewith�adjustable�pointers�on�eachend.�It�is�used�for�making�point-to-point�measurements.

• may�require�a�tape�measure�tomeasure�between�the�pointers.This�is�used�for�tram�gauges�that

do�not�have�a�built-in�measuringdevice.

• is�available�in�different�sizes.• may�be�digital�or�equipped�with�abuilt-in�tape�measure.

• often�have�metric�measurementsprinted�on�the�bar�and�pointers.

On�holes,�measure�from�edge�to�edge�or�center�tocenter.

Point-to-point�measurements�for:

• holes�of�the�same�size�are�madeeither�edge�to�edge�or�center�tocenter.

• fasteners�will�typically�be�center�tocenter,�measuring�to�the�center�ofeach�bolt�head.

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Measuring�between�holes�of�different�sizes�requiresmaking�the�proper�calculations.

To�measure�between�reference�holesthat�are�different�sizes,�make�twomeasurements�where�the:

• first�measurement�is�made�fromthe�inside�edge�of�one�hole�to�theinside�edge�of�the�other�hole.

• second�measurement�is�made�fromthe�outside�edge�of�one�hole�to�theoutside�edge�of�the�other�hole.

Add�the�two�measurements�together,then�divide�by�two.�This�calculation�willprovide�a�center-to-center�measurementfor�two�reference�holes�that�are�differentsizes.�Typically,�this�type�of�measurementis�not�found�in�dimension�guides�andis�used�for�comparison�measurementsonly.

Refer�to�the�"Video:�Making�Point-To-Point�Measurments�-�Part�1"�in�thepresentation�for�a�video�on�how�to�makequick�point-to-point�measurements�toidentify�potential�structural�damage.

Refer�to�the�"Video:�Making�Point-To-PointMeasurments�- Part�2"�in�the�presentationfor�a�video that�concludes�the�discussionon�how�to�properly�make�quick�point-to-point�measurements�to�identify�potentialstructural�damage.

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Common�point-to-point�measurements�include�dooropenings�(left)�and�specific�points�beneath�the�hoodsuch�as�the�radiator�core�support�mounting�points(right).

Common�point-to-point�measurementsused�to�perform�quick�checks�forstructural�damage�include:

• lower�ball�joint�to�frame.• underhood�crosscheck.• underbody�crosscheck.• door�and�deck�lid�openings.

Point-to-point�measurements�can�alsobe�comparative�measurements�from�sideto�side.�Point-to-point�measurementsshould�not�be�a�substitute�for�three-dimensional�measurements,�a�requirementfor�structural�alignment.

This�is�a�three-dimensional�measuring�system�thatcan�be�used�for�damage�analysis.

There�are�several�types�of�three-dimensional�measuring�systems�usedto�measure�a�vehicle�and�return�it�toproper�dimensions.�Each�of�these�systemsuses�a�specific�method�for�providingmeasurement�readings�to�the�technician.Some�of�these�systems�include:

• universal�mechanical�or�laser.• fixture�measuring�systems.�This�isnot�commonly�used�for�damageanalysis�as�it�requires�the�vehiclebe�mounted�to�a�bench.

• computerized�measuring�systems.

Each�of�these�systems�must�read�all�threedimensions�to�verify�a�specific�point�on�avehicle.�These�dimensions�include�height,width,�and�length.

Three-dimensional�measuring�equipmentmay�be�installed�in�the�estimating�bay�toassist�in�writing�accurate�damage�reports.This�type�of�equipment�generally�does�notrequire�anchoring�the�vehicle�in�place.

Examples�of�measuring�equipment�fordamage�analysis�include:

• NAJA�from�Celette.• M802�with�Car-O-Tronic�from�Car-O-Liner.

• Contact�from�Car�Bench.

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The�imaginary�datum�plane�is�positioned�below�avehicle�and�is�used�to�measure�vehicle�height.

A�datum�plane:

• is�used�by�measuring�systems�as�astarting�point�from�which�heightis�measured�to�various�referencepoints�on�the�vehicle.

• is�an�imaginary�surface�or�planepositioned�beneath�the�vehiclethat�is�parallel�to�the�vehicleunderbody.

• distance�from�the�bottom�of�thevehicle�varies�according�to�themaker�of�the�measuring�system�orvehicle�maker's�dimension�guide.

The�centerline�plane�cuts�the�vehicle�in�halflengthwise,�and�is�used�to�measure�width.

Centerline�plane�is:

• an�imaginary�plane�that�cuts�thevehicle�in�half�from�the�floor�to�theroof�lengthwise,�front�to�rear.

• used�by�measuring�systemsas�a�starting�point�for�widthmeasurements.

• used�to�establish�a�width�positionfor�vehicle�reference�points.

The�zero�plane�is�used�to�measure�length�and�canbe�placed�anywhere�along�the�length�of�the�vehicledepending�on�the�measuring�equipment�maker�orvehicle�maker's�preference.

Zero�plane�is:

• used�by�measuring�systems�as�astarting�point�from�which�length�ismeasured.

• an�imaginary�plane�that�extendsacross�the�width�of�the�vehicle.

• projected�at�different�locationsdepending�on�the�maker�of�thedimension�guide.

The�zero�plane�should�not�be�in�an�areathat�has�been�damaged.�If�the�dimensionguide�shows�the�zero�plane�in�an�area

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that�has�been�damaged,�such�as�thefront�torque�box�area,�the�zero�planecan�be�moved�to�the�rear�torque�boxarea.�The�listed�measurements�in�thedimension�guide,�however,�must�beadjusted�accordingly.

Chevrolet�Tahoe�Hybrid

Three-dimensional�measuring�points�are�locatedthroughout�the�vehicle,�including�underbody�pointsas�shown�here.

Points�used�for�measuring�the�vehicleare�control�and�reference�points.�Thesepoints:

• may�be�the�same�points�usedduring�vehicle�assembly.

• are�used�for�damage�analysis.• include�bolts,�slots,�holes,�formedand�pierced�parts,�and�divots.

• generally�require�starting�withthree�known�good�points�to�set�upthe�measuring�system.

Suspension�measurements�can�be�made�from�theupper�or�lower�pivot�points�to�the�vehicle�centerline.

Similar�to�the�point-to-pointmeasurements�taken�from�the�lower�pivotpoint,�three-dimensional�measurements:

• are�made�from�the�vehiclecenterline�to�verify�properpositioning�of�the�suspension.

• can�help�determine�if�lowerrails,�strut�towers,�suspensionparts,�or�engine�cradles�are�out�ofalignment.

One�suspension�measurement�that�is�usedis�called�steering�axis�inclination�(SAI).These�points�can�be�verified�by�measuringthe�distance�from�centerline�to�the�upper(top�of�the�strut�tower)�and�lower�pivotpoints�(lower�ball�joint).�When�the�upperand�lower�pivot�points�are�at�specification,the�SAI�angle�will�be�correct.�The�purposeof�SAI�is�for�directional�control�of�thevehicle.�If�the�angle�is�different�fromside�to�side,�the�vehicle�may�pull.�SAI�ismeasured�with�true�vertical.

An�engine�cradle�that�has�moved�or�beendamaged�may�cause�an�incorrect�SAI.

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When�making�three-dimensionalmeasurements,�technicians�start�with�thecenter�section�of�the�vehicle.�This�part�ofthe�vehicle�is�essentially�the�foundationof�measuring,�and�provides�a�referencefor�all�other�measurements.�There�areinstances�when�the�center�section�isdamaged,�however,�only�three�goodpoints�are�needed�to�establish�a�goodfoundation.

More�information�on�measuring�andalignment�angles�can�be�found�in�theI-CAR�live�“Measuring�(MEA01)”�and“Wheel�Alignment�and�Diagnostic�Angles(STE04)”�training�courses.

Electronic�measuring�system�equipment�providesvehicle�specific�measurements.

Specific�points�used�to�make�three-dimensional�measurements�are�providedby:

• measuring�equipment�makers.• vehicle�makers.

Estimating�guides�and�vehicle�makersalso�provide�quick�point-to-pointmeasurements.�Measurements,�whetherthree-dimensional�or�point-to-point,

are�almost�exclusively�provided�inmillimeters.

Most�electronic�measuring�systems�set�their�tolerancerange�to�3�mm.

During�vehicle�production,�most�vehiclesare�built�within�a�certain�tolerance.Tolerance:

• is�the�range�that�a�measurementcan�vary�by�and�still�beacceptable,�so�the�vehicle�panelsfit�and�operate�properly�and�thesuspension�allows�the�vehicle�tohandle�properly.�This�may�be�aslow�as�zero,�or�no�tolerance,�forsome�vehicle�makers.

• may�include�variations�indimensions�between�vehiclesof�the�same�make.�This�is�calledvehicle�build�tolerance.

Due�to�this�tolerance,�not�all�vehiclemeasurements�will�be�identical�andmay�vary�by�a�millimeter�or�two.�Duringcollision�repairs,�the�vehicle�must�bereturned�to�proper�specification.

For�collision�repair�purposes,�tolerancedepends�on�what�is�being�measured.

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For�example,�areas�with�very�low�or�notolerance�may�include�nonadjustabledoor�hinges,�uniside�construction,nonadjustable�suspension�mountinglocations,�and�airbag�sensor�mountinglocations.

Items�with�more�tolerance�may�includerail�measurements.�However,�in�mostcases,�tolerance�will�not�exceed�±3mm.

Buick�LaCrosse

The�underhood�dimensions�for�this�vehicle�showsthat�the�strut�tower�bolt�locations�are�providingasymmetrical�measurements.

Most�points�on�a�vehicle�are�in�the�samelocation�on�the�left�and�right�side,�orsymmetrical.�Asymmetrical�vehicleshave:

• structural�variances�from�the�left�toright�side.

• reference�points�in�differentlocations.

For�example,�some�older�model�vehiclesmay�have�door�openings�with�differentdimensions�for�the�passenger�anddriver�side�door.�This�is�an�example�ofa�structural�variance.�Some�vehicles

may�have�strut�tower�bolts�in�differentpositions.�Since�the�strut�tower�boltsare�reference�points,�the�measurementsmay�be�different�even�though�there�is�nostructure�variation�between�the�left�andright�side�of�the�vehicle.

Most�computerized�measuring�systems�allowmeasurements�to�be�printed.

Most�three-dimensional�measuringsystems�offer�the�option�of�printing�outthe�measuring�results.�On�these�particularsystems:

• a�computer�is�required�to�measureand�record.

• the�readouts�vary�by�manufacturer.• improper�measurements�may�behighlighted�in�a�different�color.Some�colors�may�vary�dependingon�if�the�measurement�is�too�longor�short,�or�too�high�or�too�low.

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Measurements�that�are�out-of-specification�are�oftena�different�color�to�highlight�problem�areas.

The�measuring�printouts�note�the�specificmeasuring�locations,�and�provide�theprofile�and�overhead�view�of�the�vehicle.The�computerized�printouts:

• provide�complete�measurementsand�an�overall�picture�of�damage.

• may�have�a�negative�sign�toindicate�a�short�or�narrowmeasurement.

Some�systems�provide�a�three-dimensional�display�of�damage�once�themeasurements�are�complete.

Module�Wrap-Up

Topics�discussed�in�this�moduleincluded:

• the�different�types�of�vehicledesigns.

• how�unitized�structures�aredesigned�to�collapse.

• how�different�impact�anglestransfer�collision�energy�andcreate�different�types�of�damage.

• how�to�read�vehicle�measurementsto�determine�structural�damage.

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This�page�is�intentionally�left�blank.

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Module�2�-�StructuralDamage�Analysis

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General�Repair�Considerations

The�learning�objectives�for�this�moduleinclude:

• identifying�general�repairconsiderations�for�structural�parts.

• identifying�front�structural�partsand�common�techniques�foranalyzing�damage�from�frontimpacts.

• identifying�side�structural�partsand�common�techniques�foranalyzing�damage�from�sideimpacts.

• identifying�rear�structural�parts�andcommon�techniques�for�analyzingdamage�from�rear�impacts.

• identifying�specific�damage�todetermine�if�structural�glass�shouldbe�repaired�or�replaced.

• listing�common�types�of�damagethat�can�occur�to�body-over-framevehicles�and�determining�if�it�canbe�repaired.

Ford�Fiesta

This�shows�the�HSS�and�UHSS�inner�structures�onthe�Ford�Fiesta.

When�deciding�to�repair�parts�on�latemodel�unitized�structures,�appraisersmust�take�into�consideration�severalmore�variables�compared�to�older�modelvehicles.�These�include�the�fact�that:

• steel�parts�have�become�muchstronger,�requiring�differentdamage�analysis�and�repairtechniques.

• attachment�methods�have�beenaltered�to�reduce�the�effects�thatwelding�has�on�advanced�high-strength�steels�(AHSS).

Estimating�processes�must�also�changewith�vehicle�technology.�Old�repairstandards�of�the�past�are�no�longerviable�with�today's�modern�constructiontechnology.

Chevrolet�Malibu

This�rocker�panel�was�work�hardened�during�partforming,�and�hardened�again�from�the�collision.

Metal�is�work�hardened�each�time�it�isformed,�bent,�stretched,�or�compressed.As�a�part�becomes�more�work�hardened,it�becomes�more�brittle,�making�itprone�to�cracking.�A�metal�part�is�workhardened�initially�when�it�is�formed�at�the

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manufacturing�plant.�However,�it�is�workhardened�further�when�it�is:

• deformed�during�a�collision.• straightened�during�repair.

Work�hardening�changes�the�originalcharacteristics�of�the�part.�This�canbe�an�issue�if�the�part�is�not�repairedproperly.�A�work-hardened�part�may�notreact�properly�if�it�is�involved�in�anothercollision,�possibly�allowing�more�intrusioninto�the�passenger�compartment.�Althoughthe�effects�of�work�hardening�can�bereduced�with�the�use�of�heat,�applicationsof�heat�are�primarily�limited�to�mildsteel.

This�rail�shows�a�bend�in�the�lower�flange�area.

There�is�a�common�statement�in�thecollision�industry�that�if�a�part�is�bent,�itcan�be�straightened,�if�it�is�kinked,�it�mustbe�replaced.�A�bend:

• is�a�smooth,�continuous�change�inshape.

• can�be�repaired�without�alteringthe�state�or�shape.

The�"Demonstration:�Bent�Metal"�shows�apicture�of�what�is�classified�as�a�bend�in�asteel�part.

This�portion�of�a�frame�rail�is�kinked.

A�kink�is�defined�as�a�sharp�bend�with�asmall�radius�over�a�short�distance.

A�part�is�considered�kinked�if,�afterstraightening,�there�is�a�permanent�areaof�deformation�that�will�not�return�toits�original�shape�without�the�use�ofexcessive�heat.�The�kinked�area�hasexperienced�changes�in�the�metal,�andmay�have�visible�cracks�or�tears.�Thesechanges�create�permanent�damage�thatcannot�be�repaired�regardless�of�the�typeof�repair�performed.

The�"Demonstration:�Kinked�Metal"�showsa�picture�of�what�is�classified�as�kink�in�asteel�part.

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Ford�F-150

This�frame�rail�has�a�minor�bend�that�may�be�difficultto�straighten.

When�making�a�part�repair�decision,�themost�important�factors�to�consider�arethat�the�metal�state�and�shape�must�berestored.�In�other�words,�both�strength�andappearance�must�match�the�pre-accidentintegrity�of�the�part.

Metal�has�a�molecular�grain�structure.This�structure�gives�metal�its�strength�andcannot�be�seen�with�the�naked�eye.�Whenmetal�is�damaged,�its�grain�structure�isrearranged.�This�grain�structure�damagecan:

• weaken�the�part.• cause�the�part�to�react�differently�ifinvolved�in�another�collision.

• occur�when�an�area�is�kinked.The�grain�structure�in�kinkedareas�will�likely�be�irreversiblyaffected.�When�an�area�is�kinked,it�is�likely�to�have�microscopiccracking�of�the�grain�structure.Aluminum�is�especially�vulnerableto�this�and�will�often�crack�duringstraightening.

Some�high-strength�steel�(HSS)�and�ultra-high-strength�steel�(UHSS)�are�typicallynot�repairable�regardless�of�whether�thepart�is�kinked�or�bent.�UHSS�is�almostalways�replaced�if�damaged�due�topermanent�changes�in�the�steel.

When�taking�into�consideration�stateand�shape,�the�kink�vs.�bend�rule�is�nolonger�as�simple�as�it�sounds.�It�doesnot�always�provide�a�definitive�repairvs.�replace�answer.�For�example,�ifthe�part�is�bent,�but�the�thickness�orstrength�of�the�metal�will�not�allowfor�straightening�without�leaving�anarea�of�permanent�deformation,�thenreplacement,�either�partial�or�complete,would�be�appropriate.

Chevrolet�Corvette

If�heat�is�allowed�by�the�vehicle�maker,�the�amountof�heat�applied�should�be�monitored�to�make�sure�itdoes�not�exceed�recommendations.

HSS�and�UHSS�are�altered�by�theapplication�of�heat.�Heat�makes�HSSand�UHSS�softer,�more�malleable,�orweaker,�essentially�losing�their�hightensile�strength.

Heating�a�part�to�straighten�it�is�generallynot�recommended�unless�the�part�is

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a�mild�steel�part�where�limited�heatapplication�will�not�affect�the�integrity�ofthe�steel.

Vehicle�makers�provide�heat�limitations�in�theircollision�repair�information.

To�determine�if�heat�can�be�applied�forstress�relieving,�refer�to�the�body�repairor�service�manual.�Some�vehicle�makershave�specific�guidelines�for�heating�steelduring�repairs.�These�may�include:

• not�allowing�heat�to�be�used�forrepairs,�such�as�straighteningkinks.�The�vehicle�maker�may�onlyallow�cold�straightening.

• that�HSS�should�generally�not�beheated.

• using�heat�only�as�a�last�resort.This�may�include�using�heat�whenstraightening�the�vehicle�back�toproper�dimensions.

• the�maximum�temperature�a�partis�allowed�to�be�heated.

• the�total�amount�of�time�heat�maybe�applied.�Heating�times�aregenerally�cumulative.�This�meansthat�the�metal�can�only�be�heatedfor�the�total�time�given.�It�cannotbe�reheated�after�the�total�time�hasbeen�reached.

If�the�material�cannot�be�identified,�itshould�be�treated�as�a�type�of�HSS�and�notbe�heated.

There�are�a�variety�of�heat�monitoring�materials�andequipment�that�can�be�used�to�ensure�heat�limits�arenot�surpassed.

If�heat�is�used,�it�is�recommended�to�havethe�repair�facility�document�the�amountof�heat�applied,�the�length�of�time,�andwhere�it�is�used.�This�data�should�beattached�to�the�repair�order.

Temperature�indicators�are�recommendedto�ensure�the�heating�temperaturedoes�not�exceed�vehicle�makerrecommendations.�Temperature�indicatorsare�available:

• in�a�variety�of�temperature�ranges.• as�heat�sticks�made�of�a�waxy,chalky,�or�liquid-type�of�substance.The�substance�melts�when�therated�temperature�is�reached.

• as�thermal�paints�that�work�byeither�changing�color�or�meltingwhen�the�rated�temperature�isreached.

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• as�temperature-indicating�labelsthat�change�color�when�a�specifictemperature�is�reached.

• as�noncontact�thermometers�thatcan�detect�the�amount�of�heatradiating�from�an�object.

I-CAR�has�links�to�vehicle�maker�websites�in�additionto�information�on�which�specific�parts�have�partialreplacement�procedures.

Determining�how�damage�in�a�part�can�bereplaced�depends�on�recommendationsfrom�the�vehicle�maker.�Vehicle�makerrecommendations�can�be�found�at:

• vehicle�maker�collision�repairwebsites,�typically�for�a�nominalfee.�General�Motors�and�Chryslerbody�repair�information�is�free.The�websites�can�be�accessedfrom�the�I-CAR�website.

• ALLDATA,�which�is�a�subscriptionwebsite.

• the�Partial�ReplacementRecommendations�matrix�on�theI-CAR�website.�The�matrix�onlystates�if�partial�replacement�isallowed�by�the�vehicle�maker,and�does�not�provide�part-specificprocedures.�This�must�be�acquired

through�the�vehicle�maker�websiteor�ALLDATA.

• OEM1Stop.�This�can�be�found�atwww.oem1stop.com.

Damage�removal�is�generally�done:

• by�straightening.• at�factory�seams�by�removing�theentire�part.

• at�factory�seams�by�only�removinga�portion�of�the�part.

• by�sectioning�the�part.

Refer�to�the�presentation,�"Demonstration:Partial�Replacement�Recommendations"for�a�demonstration�that�shows�the�PartialReplacement�Recommendations�Matrix.

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Honda�Accord

The�front�rail�on�this�Honda�Accord�is�beingcompletely�replaced�at�factory�seams.

Replacing�a�complete�part�at�factoryseams:

• is�common�on�UHSS�parts,�thoughsome�vehicle�makers�offer�partialreplacement�of�their�UHSS�parts.For�example,�the�Audi�Q5�has�asectioning�procedure�for�its�UHSSB-pillar�reinforcement.

• may�be�done�becausereinforcements�make�partialreplacement�difficult.

• may�require�additionalundamaged�part�removal.

• may�require�extensive�partremoval.

• may�require�disturbing�factoryseams�that�create�additionalcorrosion�hotspots.

This�Ford�Mustang�front�rail�has�a�sectioning�joint(left),�while�this�Chevrolet�Malibu�shows�a�partialreplacement�procedure�at�factory�seams�(right).

A�portion�of�a�part�can�be�replaced�atfactory�seams,�or�a�new�joint�can�becreated�away�from�factory�seams.�This�iscalled�"sectioning."

Many�parts�of�a�vehicle�are�not�one�piece,but�composed�of�multiple�pieces�thatare�joined�together.�Replacing�a�portionof�a�part�at�factory�seams�is�sometimesrecommended.�Sectioning�does�this�atan�area�of�the�part�away�from�factoryseams,�creating�a�new�joint.�Either�ofthese�partial�replacement�methodsrequires�a�recommendation�from�thevehicle�maker,�with�either�a�procedure�oravailable�partial�part.�There�may�also�bea�recommendation�to�partially�replace�apart�at�factory�seams�at�one�location,�andsection�in�another�location.

The�advantages�of�partial�replacementincludes:

• the�repair�affects�a�smaller�area.• fewer,�undamaged�OEM�welds�aredisturbed.

• less�original�corrosion�protectionis�disturbed.

• less�disassembly�may�be�required.

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Laser-welded�joints�are�not�considered�agood�factory�seam�for�partial�replacement.Most�vehicle�makers�do�not�recommendthis�joint.

Chevrolet�Malibu

The�A-pillar�on�this�Chevrolet�Malibu�has�arecommended�sectioning�location�in�the�windshieldarea.

When�considering�if�partial�replacement�isa�viable�repair�option,�determine:

• if�a�procedure�exists�to�makethis�type�of�repair,�or�if�there�is�apartial�part�available,�such�as�aportion�of�an�assembly.

• if�the�partial�replacement�optionremoves�all�of�the�damage.

• which�joints�are�recommended.• how�corrosion�protection�will�beapplied�after�the�joint�is�complete.

Chevrolet�Malibu

The�cutting�of�an�access�window�in�the�roof�rail�isrecommended�on�this�Chevrolet�Malibu�to�install�theB-pillar.

Some�repair�procedures�from�vehiclemakers�have�been�developed�that�requirecutting�access�windows�into�a�part�toaccess�the�opposite�side�of�a�part.�This�isgenerally�done�to�allow�access�to�a:

• reinforcement�for�sectioning.• part�so�that�it�can�be�removedfor�complete�replacement.�Forexample,�on�the�2009�HondaAccord,�access�windows�in�theouter,�upper�B-pillar�are�requiredfor�removing�the�reinforcement.�Asimilar�method�is�used�to�accessthe�rocker�panel�reinforcementon�this�vehicle.�These�are�vehiclemaker-approved�access�windows.

Toyota�also�has�a�procedure�for�cutting�anaccess�window�to�reach�the�offset�jointon�the�rocker�panel�reinforcement.�Thisis�because�the�replacement�outer�panel,due�to�how�it�is�cut�at�the�factory,�may�notextend�over�the�reinforcement�area.�Thisprocedure�is�recommended�on�severalToyota/Lexus/Scion�vehicles.

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Cutting�any�type�of�access�window�istechnically�considered�a�sectioning�joint,and�can�be�more�intrusive�since�a�windowhas�two�or�more�cuts�compared�to�justone�in�a�traditional�sectioning�joint.�Re-welding�all�these�cuts�creates�a�largerheat-effect�zone,�which�can�be�damagingto�higher�strength�steels.�It�also�requires�alarger�area�to�be�cosmetically�finished.

For�these�reasons,�this�procedure�is�doneonly�when�recommended�by�the�vehiclemaker.

Recycled�assemblies,�such�as�this�radiator�coresupport,�are�often�used�for�collision�repairs.

Recycled�assemblies�are�used�forvehicle�repairs.�While�generally�notrecommended�among�vehicle�makers,�itis�a�reality�of�the�collision�repair�industry,and�is�used�to�reduce�the�number�of�totallosses�by�providing�a�more�economicalternative.

It�can�also�be�a�less�intrusive�repair.�Forexample,�using�a�recycled�assembly�mayrequire�fewer�spot�welds�to�be�removedcompared�to�removing�and�replacingmultiple�panels�individually.

If�recommending�a�recycled�assembly,note�that�there�may�be�additional�stepsrequired,�such�as�cleaning�up�the�part,trimming�the�part�for�proper�fit,�removingany�mild�surface�corrosion,�and�removingattached�trim�or�unwanted�panels.�Therecycled�part�must�be�in�good�condition,such�as�no�structural�damage�of�any�kind,if�it�is�going�to�be�used.

Note�that�when�ordering�recycled�parts,the�parts�may�not�be�the�same�design�evenif�they�are�from�the�same�model�year.�Onoccasion,�there�are�model�changes�withinthe�same�model�year.�There�are�alsodifferent�trim�levels�that�must�be�takeninto�consideration�when�determining�if�arecycled�part�can�be�used.

More�information�on�the�use�of�recycledparts�for�collision�repair�can�be�found�inthe�I-CAR�live�"Recycled�Parts�for�CollisionRepair�(RCY01)"�training�course.

A�corroded�panel�may�be�an�indication�that�the�partwas�damaged�from�a�previous�collision.

Items�to�consider�when�inspectingcollision-damaged�parts�include:

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• corrosion�that�may�affect�therepair�process�or�indicate�previousdamage.

• previous�repairs�that�may�affecthow�repairs�will�be�made�to�thenew�damage.�Previous�repairs�areoften�indicated�by�plug�welds,flange�variations,�or�a�thickerfinish�that�requires�identificationusing�a�film-thickness�gauge.�If�apart�was�previously�repaired,�thesame�repair�may�not�be�possible.For�example,�instead�of�sectioningin�the�same�location,�completepart�replacement�may�be�the�onlyoption.

• damage�to�the�vehicle�finish.• damage�to�suspension�orsuspension�mounting�locations.Make�sure�that�the�steering�wheelis�in�the�straight-ahead�position,and�check�the�position�of�the�frontwheels.

Taking�pictures�(left)�and�disassembling�parts�(right)may�be�part�of�performing�a�thorough�damageanalysis.

To�ensure�that�there�are�no�delays�inthe�repair�process,�a�thorough�damageanalysis�is�required�to�ensure:

• all�the�necessary�parts�havebeen�ordered.�This�requiresfinding�any�hidden�damage.�Itis�important�to�note�that�up�to40%�of�collision�damage�can�belocated�underneath�the�vehicle.

• an�accurate�report�is�written.This�ensures�that�the�repairs�arecompleted�within�expectations�ofthe�customer.�Finding�significantdamage�after�the�repairs�havestarted�will�delay�delivery�time.

• any�sublet�work�is�scheduled.

A�process�known�as�"blueprinting"�allowsthe�estimator�and�repair�facility�to�seethe�entire�repair�picture�before�repairsare�started�and�ensures�that�the�vehicle,once�repairs�have�been�started,�will�notbe�held�up�to�wait�for�additional�partsto�be�ordered�or�sublet�procedures�tobe�performed.�Blueprinting�includesan�orderly�teardown,�which�can�playan�important�role�in�identifying�hiddendamage.�Removing�bolt-on�parts,�such�asfenders,�bumpers,�doors,�etc.,�can�showdamage�that�is�otherwise�undetectable.

For�more�information�on�blueprinting,consider�attending�the�I-CAR�live"Overview�Of�Cycle�Time�ImprovementFor�The�Collision�Repair�Process�(CYC01)"training�course.

Performing�an�accurate�estimate�requiresfollowing�a�specific�sequence,�mostcommonly,�starting�at�the�area�of�directdamage�and�working�toward�the�oppositeside�of�the�vehicle.�The�next�step�is�to�lookon�top�and�underneath�the�vehicle.�From

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there,�the�inspection�continues�to�thevehicle�interior.�It�also�may�be�helpful�toinspect�the�vehicle�from�a�distance�so�theentire�vehicle�can�be�seen.�This�providesa�broader�perspective�of�the�damage,and�may�provide�a�better�view�of�theoverall�damage�condition.�For�example,�ifthe�vehicle�is�sagging�or�a�portion�of�thevehicle�is�lower�on�one�side,�a�close-upinspection�may�not�reveal�this.

Front�Impact

This�shows�the�parts�commonly�associated�with�aunitized�front�structure.

Front�impacts�commonly�damage�one�ormore�of�the�following�parts�of�the�unitizedstructure:

• Bumper�reinforcement• Front�rails�-�upper�and�lower• Radiator�core�support• Engine�mounts• Front�suspension• Engine�cradle

Collision�energy�is�designed�to�be�absorbed�andtransferred�to�other�areas�of�the�vehicle.

This�front�structure�is�designed�toabsorb�collision�energy�by�partiallycollapsing,�followed�by�transferring�theremaining�energy�around�the�passengercompartment.�All�these�parts�have�specificfunctions,�but�they�also�work�together�toabsorb�the�impact,�so�it�is�key�that�theyare�restored�to�proper�state�and�shapeso�that�they�maintain�their�integrity�andperform�as�intended�in�a�subsequentcollision.

Toyota�RAV4

This�shows�a�bolt-on�radiator�core�support�withupper�and�lower�tie�bars,�and�side�panels.

The�radiator�core�support�on�a�unibodyvehicle�generally�consists�of:

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• an�upper�tie�bar�that�connects�theupper�rails�on�both�sides�together.

• a�lower�tie�bar�where�the�radiator,air�conditioning�(A/C)�condenser,and�other�coolers�are�fastened.

• side�panels�on�some�designs.

The�radiator�core�support�can�be�weldedor�bolted�to�the�vehicle�structure.

Radiator�core�supports�may�be�made�fromseveral�different�materials,�including�steel,aluminum,�magnesium,�plastic,�carbonfiber,�and�composite.

Chevrolet�Malibu

Some�radiator�core�supports�allow�parts�of�theassembly�to�be�serviced�separately.

The�material�type�should�be�consideredwhen�making�repair�versus�replacedecisions.�For�example,�minorstraightening�of�a�steel�part�may�beallowed,�however,�a�cracked�magnesiumor�composite�radiator�core�support�isgenerally�replaced.

Considerations�include�replacing�onlythe�damaged�portion�of�the�radiator�coresupport,�if�provided�by�the�vehicle�maker.Replacement�of�one�side�may�eliminate

having�to�remove�the�fender�and�otheradjacent�parts�on�the�opposite�side.This�may�be�done�along�factory�seams.Generally�speaking,�this�option�is�modelspecific.�For�example,�the�AdvancedCompatibility�Engineering�(ACE)�bodystructure�from�Honda�does�not�allow�forreplacement�of�specific�individual�parts.

Adjacent�parts�for�removal�include�theradiator,�fluid�coolers,�A/C�condenser,hood�latch,�bumper�assembly,�fenders,and�electronics.

It�is�also�important�to�remember�to�re-order�labels�for�the�upper�tie�bar�if�it�isreplaced.

Toyota�Camry

This�is�the�upper�rail�for�a�Toyota�Camry.

The�upper�rails:

• connect�the�cowl�(and�/�or�innerA-pillar)�to�the�radiator�coresupport.�They�are�generallywelded�in�place.

• are�the�attachment�point�for�thefenders�and�hood.

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• have�several�different�designs,depending�on�the�type�of�unitizedstructure.

• may�be�made�from�mild�steel�orHSS.

• are�designed�to�absorb�energy�andtransfer�the�energy�to�other�areasof�the�structure.

The�upper�rails�on�a�body-over-framevehicle:

• make�up�part�of�a�unitized�cabstructure.

• may�be�welded�to�the�pillars�andradiator�core�support.

• may�be�integrated�into�the�fenderor�fender�reinforcement�panels.General�Motors�typically�uses�thisdesign�on�the�C�/�K�series�trucksand�SUVs.

Chevrolet�Cobalt

This�is�the�sectioning�location�for�the�upper�rail�onthe�Chevrolet�Cobalt.

When�making�repair�and�replacedecisions�on�the�upper�rail:

• sectioning�options�may�beavailable�depending�on�thevehicle�maker.�While�not�the�mostcommon�type�of�repair,�there�aresome�procedures�available.

• it�may�be�allowed�to�just�replacethe�outer�or�inner�portion�of�therail.

• replacement�procedures�generallyrequire�separation�from�the�struttower.

• straightening�may�be�possibledepending�on�the�steel�strength,but�note�heat�considerations�or�ifheat�may�be�used�at�all.

Cadillac�SRX

The�crush�box,�such�as�on�this�Cadillac�SRX,�is�asacrificial�piece�that�is�replaced�when�damaged.

At�the�front�of�the�vehicle,�there�may�be�apart�called�a�crush�box.�This�piece�is:

• a�sacrificial�piece�on�the�end�ofthe�front�lower�rail.

• designed�to�collapse�beforetransferring�damage�to�the�frontrail,�minimizing�structural�damagein�lower�speed�collisions.

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• either�bolted�or�welded�to�thebumper�reinforcement.�Toyotahas�bolt-on�crush�boxes�featuredon�many�of�their�late�modelvehicles.�The�Toyota�Tundra�has�analuminum�crush�box�that�is�partof�the�bumper�reinforcement.�The2011�Ford�Fiesta,�in�addition�toother�Ford�models,�has�a�bolt-oncrush�box.�Some�older�model�GMfull-frame�vehicles�have�weld-oncrush�boxes.�Audi�uses�bolt-oncrush�boxes�for�their�aluminumvehicles.

• replaced�if�damaged.�Do�notstraighten�a�damaged�crush�box.

Audi�A5�Cabriolet

This�is�the�lower�rail�on�the�Audi�A5�Cabriolet.

Front�lower�rails�extend�out�near�thebottom�of�the�front�section.�The�lower�railsmay:

• be�made�of�different�shapesor�thicknesses�of�metal�that�isdesigned�to�absorb�or�redirectmuch�of�the�front�impact�energy.

• have�crush�initiators�that�cause�thepart�to�collapse�in�a�predictable

manner,�thus�absorbing�collisionenergy.

• have�lateral�and�longitudinalstiffeners�that�direct�the�energy�toanother�part�of�the�structure.

• have�tailor-welded�blanks,�wheredifferent�types�or�thicknesses�ofmetal�are�joined�together�with�alaser�weld.

• use�mild,�HSS,�or�AHSS.• have�sectioning�procedures.�Manymodels�have�multiple�optionallocations,�however,�some�donot�recommend�any�sectioninglocations,�requiring�the�completerail�assembly�to�be�replaced.

• may�allow�replacing�either�theinner�or�outer�portion�of�the�rail.

It�is�recommended�to�only�follow�thepart�replacement�guidelines�outlined�bythe�vehicle�maker.�If�a�vehicle�makerdoes�not�offer�sectioning�guidelines,�thensectioning�should�not�be�done.

Cadillac�DTS

This�is�the�strut�tower�on�a�Cadillac�DTS.

The�strut�towers:

• are�used�with�McPherson�strut-type�suspensions.

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• have�the�top�of�the�strut�fastenedto�the�strut�tower.

• are�the�upper�pivot�point�for�thesteering�axis.

• are�generally�replaced�whendamaged.

Strut�tower�position�is�critical�for�properalignment�and�affects�alignment�anglessuch�as�SAI,�caster,�or�camber.�Underhoodmeasurement�quick�checks�can�be�madeto�determine�if�the�strut�tower�has�moved.This�requires�measuring�from�strut�towerfastener�to�strut�tower�fastener,�as�wellas�measuring�to�other�areas�under�thehood.�Point-to-point�specifications�can�befound�in�vehicle�service�information�orestimating�guides.

Strut�towers�are�commonly�made�fromstamped�steel.�However,�some�vehiclemodels,�such�as�the�BMW�5�and�6�Series,are�made�from�cast�aluminum.

Considerations�for�replacing�thestrut�tower�assembly�may�includedetermining:

• if�partial�replacement�is�an�option.Depending�on�vehicle�makerrecommendations,�the�design�ofthe�part,�and�the�extent�of�damage,partial�replacement�at�factoryseams�or�sectioning�may�be�anoption.

• the�shape�and�configuration�ofthe�front�apron�panel,�forwardof�the�strut�tower.�This�portion�istypically�light�gauge�construction.Flat�areas�may�be�able�to�be

straightened.�Some�apron�panelsare�highly�formed�and�difficult�tostraighten.

This�is�the�apron�on�a�Jaguar�XF.

The�fender�apron,�also�called�a�skirt:

• fills�in�area�between�strut�towerand�radiator�core�support.

• connects�upper�and�lower�rails.• adds�rigidity�to�the�front�structure.

Minor�repairs�may�be�possible.

This�is�the�cowl�panel�on�the�Jaguar�XF.

The�cowl:

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• separates�the�engine�compartmentfrom�the�passenger�compartment.

• is�designed�to�reduce�noise,vibration,�and�harshness�(NVH),as�well�as�preventing�enginecompartment�fumes�from�enteringthe�passenger�compartment.

Cowls�may:

• be�multi-piece,�which�is�common.The�cowl�may�have�one�ormultiple�layers�of�sheet�metal.

• be�constructed�of�laminatedsteel,�though�this�is�rare.�The2011�Cadillac�DTS�and�the�2011Chevrolet�Malibu�are�examples�ofvehicles�with�cowl�panels�made�oflaminated�steel.

• include�a�cross-car�beam�orinstrument�panel�frame,�made�ofsteel�or�magnesium.

• have�VIN�plates�or�labels�that�mayrequire�removal.�VIN�replacementis�regulated�by�state,�federal,provincial,�and�local�laws.

The�cowl�panel�is�not�often�repaired.Damage�that�radiates�that�deep�into�thevehicle�structure�may�have�too�many�otherissues,�and�often�times�the�vehicle�is�atotal�loss.�Any�repair�to�the�cowl�generallyrequires�removal�of�the:

• engine�and�transmission�assembly.• windshield.• heating,�ventilating,�and�airconditioning�(HVAC)�parts.

• instrument�panel.

Volvo�S40

This�is�an�engine�cradle�on�the�Volvo�S40.

The�engine�cradle:

• is�used�to�hold�the�engine�inplace.

• attaches�to�the�front�lower�rails.• may�also�be�called�a�subframe.• is�made�from�either�aluminum,steel,�or�magnesium.

• is�very�difficult�to�straighten,so�replacement�is�common.Some�vehicle�makers�specificallyprohibit�straightening�the�enginecradle.

• dimension�specifications�aredifficult�to�find.

• may�contain�the�engine�mounts,lower�control�arms,�and�steeringrack�mounts.

• must�be�properly�aligned.

Some�engine�cradle�bolts�have�a�blueor�reddish�coating�on�the�threads.�Thisis�an�adhesive�that�is�used�to�hold�thebolt�in�place.�For�this�reason,�the�fastenermay�be�one-time�use�depending�on�thevehicle�maker�recommendations.�Thismay�not�be�a�vehicle�maker-specific

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recommendation,�but�rather�a�model-specific�recommendation.�For�example,the�2011�Ford�Explorer�requires�newreplacement�bolts�once�the�existing�boltsare�removed,�whereas�the�2011�Ford�Edgeallows�the�re-use�of�the�engine�cradlebolts.

Refer�to�the�presentation,�"Video:�FrontStructure�Damage�Analysis�-�Part�1"�thatshows�how�to�perform�a�front�structuraldamage�analysis�on�a�2010�Ford�Taurus.

Refer�to�the�presentation,�"Video:�FrontStructure�Damage�Analysis�-�Part�2"which�concludes�the�discussion�on�howto�perform�a�front�structural�damageanalysis.

Audi�Q5

An�estimator�is�examining�the�suspension�on�an�AudiQ5.

When�analyzing�the�front�structure�fordamage:

• start�at�the�area�of�impact�andwork�toward�the�rear�of�thevehicle.

• visualize�the�direction�of�impact.• check�the�operation�of�the�doors,hood,�and�trunk.�Do�not�operatethe�closure�panel�if�opening�it�willcause�additional�damage.

• the�fender-to-door�gap�is�the�mostcommon�indicator.

Side�Impact�Damage�Analysis

This�shows�the�parts�commonly�associated�with�aunitized�side�structure.

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Pillars�and�rocker�panels�are�part�ofthe�passenger�compartment�structure.To�protect�the�vehicle�occupants,�thepassenger�compartment�must�remainintact.�A-,�B-,�C-,�and�D-pillars,�along�withrocker�panels:

• may�have�a�one-�or�two-pieceuniside�for�the�outer�paneldepending�how�the�quarter�panelis�attached,�but�most�have�multiplereinforcements.

• may�use�multiple�reinforcementsmade�from�HSS�and�UHSS.�Thismay�include�inner�and�outerreinforcements.

• use�inner�panels�to�close�out�thebackside�of�the�part.

• provide�a�stiff�structure�thatprevents�intrusion�into�thepassenger�compartment.�Theseparts�are�also�designed�to�transfercollision�energy�to�other�areas�ofthe�vehicle.

• support�the�structure.�Pillars�arealso�designed�to�prevent�thecollapse�of�the�roof�structureduring�a�rollover.�Convertiblesdo�not�have�B-pillars�that�extendto�the�roof.�For�these�types�ofvehicles,�A-pillars�with�UHSSreinforcements�along�with�othersafety�features�may�be�used�forsupporting�the�roof�structure.

There�are�federal�standards�fromthe�National�Highway�Traffic�SafetyAdministration�(NHTSA)�that�must�be�metto�ensure�the�passenger�cab�maintainsits�integrity�in�a�rollover�accident.�Thisis�known�as�Standard�216�that�requires

every�vehicle�roof�structure�to�be�ableto�withstand�one-and-one-half�timesits�weight.�Vehicles�with�good�ratingsfrom�the�Insurance�Institute�for�HighwaySafety�(IIHS)�can�withstand�at�least�twicethe�weight�of�the�vehicle.�IIHS�did�notstart�including�this�criteria�in�its�safetyperformance�evaluations�until�2010.

Pillars�and�rocker�panels�may�be�referredto�by�different�names.�Examples�includereferring�to�the�upper�A-pillar�as�the“windshield�post,”�and�the�B-pillar�asthe�“center�post.”�Rocker�panels�aresometimes�called�“sill�panels.”

Chrysler�300

This�is�a�partial�uniside�for�the�Chrysler�300.

A�uniside�is�a�one-piece�seamlessstructure�that�typically�includes�the�pillars,rocker�panel,�and�roof�rail.�The�quarterpanel�may�also�be�included�in�a�uniside.These�are�available�for�both�full-frameunitized�structures�and�unibodies.�Unisideconstruction:

• reduces�the�amount�of�individualparts�and�body�seams.

• enables�vehicle�makers�toassemble�vehicles�with�closetolerances.

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• may�be�designed�with�tailor-welded�blanks.�This�is�doneat�the�factory�by�laser�weldingseparate�pieces�of�steel�to�form�asingle�part.�Unisides�made�in�thisfashion�have�different�strengthsor�thicknesses�designed�into�onepart.�The�2009�Ford�Mustang�usestailor-welded�blanks�for�its�unisideconstruction.

• may�be�serviced�as�an�assemblyor�as�individual�parts.�For�repairs,some�vehicle�makers�offer�eitheran�entire�uniside�or�separatereplacement�parts.�Partial�unisideassemblies�may�be�available�aswell.

• may�be�able�to�be�sectionedaccording�to�damage,�not�specificmeasurements.�For�example,Ford�recommends�that�sectioninglocations�be�determined�based�onthe�replacement�part�available�andthe�amount�of�damage.

After�unisides�are�built�at�the�factory,they�are�joined�to�the�floor�and�roof�sub-assemblies.

The�A-pillar�supports�the�roof�structure�and�thewindshield.

A-pillars�are�designed�to�support�the:

• windshield.• front�of�the�roof.• front�door�hinges.• apron�assembly.• cowl�assembly.

Restraint�systems�may�be�positioned�behind�the�A-pillar�trim.

A-pillars�are�made�from:

• mild�steel.• HSS.• UHSS.

When�making�repairs�to�A-pillars:

• note�that�the�instrument�panel�isgenerally�removed�if�the�inner�A-pillar�must�be�replaced.

• note�that�most�A-pillars�containreinforcements�that�can�affectrepair�decisions.

• there�may�be�curtain�airbagsbehind�the�A-pillar�trim,�so�theairbag�system�must�be�deactivatedand�the�airbag�module�removedwhen�working�in�this�area,

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provided�the�airbag�system�has�notdeployed.

• there�may�be�structural�foamsinside�the�pillar�that�may�requireremoval�and�reinstallation.Technicians�will�be�able�to�identifythis�in�the�vehicle�collision�repairinformation.

Audi�A5�Cabriolet

The�A-pillar�on�the�Audi�A5�Cabriolet�has�a�tubularreinforcement.

The�A-pillars�on�convertible�vehiclesare:

• designed�to�maintain�their�integrityin�a�rollover�to�prevent�the�roofstructure�from�collapsing.

• may�have�a�tubular�shapereinforcement.

• may�be�two-part�construction.• may�be�multi-part�constructionthat�includes�an�inner,�outer,�andreinforcement.

Chevrolet�Camaro

The�Chevrolet�Camaro�has�a�sectioning�procedurefor�the�A-pillar.

When�repairing�the�A-pillar:

• sectioning�joints�are�often�made�inthe�windshield�area�and�near�therocker�panel.

• the�windshield�is�generallyremoved.

• the�outer�A-pillar�should�nothave�body�filler�in�the�windshieldflange.�This�is�due�to�adhesionissues�between�the�body�filler�andthe�A-pillar�for�best�adhesion�ofthe�windshield.

• topcoats�are�generally�notapplied�in�the�exterior�windshieldpinchweld�flange.�Most�vehiclemakers�recommend�this�for�bestadhesion�of�the�windshield.One�vehicle�maker,�Audi,recommends�applying�topcoats�onthe�windshield�pinchweld.

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Chevrolet�HHR

This�is�the�UHSS�B-pillar�for�the�Chevrolet�HHR(left).�This�steel�cutaway�shows�the�reinforcementscommonly�used�for�the�B-pillar�(right).

The�B-pillar:

• has�an�inner�panel,�an�outer�panelthat�is�generally�part�of�a�uniside,and�at�least�one�reinforcement.

• reinforcement�is�generally�HSS�orUHSS.

• is�designed�so�that�there�isminimum�intrusion�into�thepassenger�compartment.

• may�be�tailor-rolled�or�tailor-welded,�hot�formed,�etc.

• on�convertibles,�is�the�lock�pillarand�is�also�made�out�of�HSS�orUHSS.

Toyota�Venza

Some�B-pillars�are�designed�to�have�varyingthicknesses�throughout�the�part�such�as�this�DodgeCaliber�B-Pillar�(left).�This�shows�the�B-pillar�androcker�panel�sectioning�location�on�the�Toyota�Venza(right).

The�B-pillar�is�designed�with�strategicplacement�of�different�strengths�andthicknesses�of�steel.�These�determine�thecollapse�zone�of�the�pillar.�Most�pillarsare�designed�to�have�slight�intrusion�at�thebottom�of�the�pillar,�near�seat�level,�whilemaintaining�integrity�at�the�top�near�theoccupants'�upper�torso�and�head.

It�is�important�to�determine�if�damage�islimited�to�the�outer�panel,�or�if�it�radiatesdeeper�into�the�reinforcement.�Unlessthere�is�specific�design�information�thatshows�how�close�the�reinforcement�isto�the�outer�panel,�it�may�be�difficultto�determine�if�the�reinforcement�isdamaged.�This�may�require�cutting�anaccess�window�to�see�if�there�is�damagebehind�the�uniside.�The�access�hole�is�cutin�an�area�of�the�outer�panel�that�is�goingto�be�replaced.

For�repairs,�the�B-pillar�reinforcementsectioning�procedures�are�limited.Most�vehicle�makers�require�complete

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replacement�of�the�reinforcement�if�it�isdamaged.�If�no�recommendations�existfrom�the�vehicle�maker,�the�part�shouldbe�replaced�at�factory�seams.�Toyota�doesnot�recommend�any�sectioning�of�B-pillarreinforcements�with�strengths�of�980�MPaor�590�MPa.�There�may�be�a�sectioningprocedure�on�440�MPa�reinforcements,�ora�portion�of�the�reinforcement�that�is�440MPa,�but�this�can�only�be�done�if�thereis�a�procedure�specified�in�the�Toyotaservice�information.

If�repair�procedures�are�provided�by�thevehicle�maker,�most�will�be�accompaniedwith�specific�recommendations�forwelding�to�minimize�the�heat-effect�onthe�high-strength�steel.�For�example,�Audihas�a�sectioning�procedure�for�the�B-pillar�reinforcement�on�the�Q5,�however,a�second�complete�reinforcement�isinstalled�behind�the�sectioning�joint.

Honda�Pilot

This�shows�the�C-�and�D-pillars�on�the�Honda�Pilot.

A�C-�or�D-pillar�is�defined�as�being�eitherof�the�two�pillars�that�support�the�reardoor�striker�and�the�roof.�Common�to�theother�pillars�on�the�side�of�the�vehicle,�theC-�and�D-pillars�use�different�strengthsand�thicknesses�of�steel.

Two-door�C-pillar�designs�may�includethe:

• sail�panel.• side�glass.• quarter�panel�or�side�panel.• rear�gate�or�hatch�frame.

Four-door�C-pillar�designs�may�includethe:

• dog�leg�area.• sail�panel.• side�glass.• door�opening�or�side�aperturepanel.

• quarter�panel�or�side�panel.• rear�gate�or�hatch�frame.

Buick�LaCrosse

Some�C-pillar�assemblies�have�restraint�systemsattached�to�the�inner�side�of�the�panel.�Thesegenerally�require�disabling�the�restraint�systembefore�beginning�repairs.

When�determining�procedures�forrepairing�the�C-�and�D-pillars:

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• inner�assemblies�are�generallyreplaced�at�factory�seams.

• outer�panels�may�be�separatedfrom�the�quarter�panel�at�the�roof-to-pillar�seam.

• outer�panels�may�be�included�withthe�replacement�quarter�panel.

• airbag�systems�may�need�to�bedeactivated�so�that�inflators�can�beremoved�before�work�begins.

• the�backglass�typically�requiresremoval�for�C-�and�D-pillarinstallation.

Chevrolet�Camaro

To�reduce�noise,�foams�may�be�placed�on�the�sailpanel�backside�such�as�on�this�Chevrolet�Camaro.

Additional�considerations�for�C-�and�D-pillar�repair�or�replacement�proceduresinclude:

• removing�adjacent�parts.�Adjacentparts�may�require�removal�whenreplacing�parts�at�factory�seams.For�example,�the�roof,�rockerpanel,�or�quarter�panel�mayrequire�removal�to�gain�access�to�apillar.�Interior�trim�will�also�likelyrequire�removal.

• foam.�Pillars�may�be�filled�withfoam.�Foam�that�is�removed�duringthe�repair�process�should�bereplaced�with�the�same�type�andamount�of�foam.�Some�types�offoam�are�used�to�increase�thestrength�of�a�structural�part,�whileother�foams�are�used�to�controlNVH.�Identifying�the�foam�typemay�be�required�by�the�repairtechnician�if�not�called�out�by�thevehicle�maker.

On�some�vehicles,�to�remove�the�outerC-�and�D-pillar�panel,�the�roof�paneloverlaps�the�outer�panel.�This�requiresremoval�of�enough�roof�panel�flange�spotwelds�to�gain�access�to�the�outer�panel,while�being�careful�to�not�damage�theroof�panel.�The�same�may�be�an�issuewith�the�B-pillar.�In�some�instances,�just�aportion�of�the�roof�can�be�lifted�to�removethe�part.�In�others,�the�entire�roof�panelmay�have�to�be�removed.

Refer�to�the�presentation,�"Video:�C-PillarDamage�Analysis�-�Part�1"�which�showshow�to�determine�if�damage�extends�deepinto�the�vehicle�structure.

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Refer�to�the�presentation,�"Video:�C-Pillar�Damage�Analysis�-�Part�2"�whichcontinues�the�discussion�on�analyzingthe�C-pillar�damage�on�the�ChevroletMalibu.

Refer�to�the�presentation,�"Video:�C-Pillar�Damage�Analysis�-�Part�3"�whichconcludes�the�discussion�by�identifyingthe�extent�of�damage�to�the�C-pillarstructure.

Chevrolet�Camaro

This�shows�the�UHSS�rocker�panel�reinforcementon�the�Chevrolet�Camaro�(left).�This�cross-sectionof�a�rocker�panel�shows�the�interior�reinforcements(right).

The�rocker�panel:

• may�be�two-part�or�multi-partconstruction.�Outer�rocker�panelsare�generally�part�of�a�uniside.�Toobtain�the�rocker�panel,�it�mayrequire�ordering�an�entire�uniside.

• has�an�UHSS�reinforcement�onmost�late�model�vehicles.

• may�have�multiple�reinforcementsat�the�base�of�the�pillars.

Chrysler�300M

Foam�is�often�used�in�the�rocker�panel�to�reduceroad�noise.

Considerations�for�rocker�panel�repair�orreplacement�procedures�include:

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• adjacent�part�removal.�Parts�thatmay�require�removal�beforerepairing�or�replacing�the�rockerpanel�include�the�doors,�fender,quarter�panel,�and�interiortrim.�On�the�2010�ChevroletMalibu,�the�quarter�panel�must�beremoved�to�remove�and�install�therocker�panel�reinforcement.

• side�airbag�sensors.�Side�impactsensors�may�be�located�on�or�nearthe�rocker�panel.�Side�impactsensors�are�typically�replaced�afterside�airbag�deployment.

• how�it�is�attached�to�the�floor�pan.• foam.�Some�rocker�panels�arefilled�with�foam.�Foam�that�isremoved�during�the�repair�processshould�be�replaced�with�thesame�type�and�amount�of�foam.Identifying�foam�type�may�berequired�by�the�repair�technicianif�not�called�out�by�the�vehiclemaker.

• multiple�sectioning�locationsare�often�provided�for�the�outerrocker�panel�and�some�innerrocker�panels.�Reinforcementsectioning�may�be�more�limiteddepending�on�vehicle�makerrecommendations.

• vehicle�makers�may�recommendto�section�according�to�damage.

The�floor�pan�can�be�damaged�from�side�impacts�asthe�B-pillar�pushes�inward.

When�inspecting�floor�pans,�look�for:

• dimensional�alignment.�Referto�vehicle-specific�serviceinformation�for�vehicledimensions.

• damaged�undercoating.�Itis�important�that�damagedundercoating�be�replaced�toprotect�underbody�parts�fromcorrosion.

• cracked�or�missing�seam�sealer.It�is�important�that�cracked�ormissing�seam�sealer�or�sound-deadening�material�be�replaced.This�is�to�ensure�that�parts�areprotected�from�corrosion�andthe�sound�level�of�the�passengercompartment�is�maintained.

• damaged�carpeting.• damaged�crossmembers.�Floorcrossmembers�may�be�made�ofHSS�or�UHSS�and�are�consideredstructural.

Some�floor�pans�are�attached�to�cowlpanels�that�are�made�from�laminated�steel.Refer�to�vehicle�maker�recommendationsto�determine�which�joining�process

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should�be�used�for�repairs�involvingattachment�to�laminated�steel.

Chevrolet�Corvette�Z06

This�shows�the�floor�pan�being�replaced�on�aChevrolet�Corvette�Z06.

Factors�to�consider�when�determiningwhether�to�repair�or�replace�floor�pansmay�include:

• part�availability.�Some�vehiclemakers�provide�replacement�partsfor�floor�pans.�Replacement�floorpans�may�be�provided�as�one-piece�or�multiple�panels.

• replacement�procedures.Replacement�procedures�for�frontfloor�pans�are�typically�doneat�factory�seams.�Some�vehiclemakers�may�provide�replacementfloor�pans,�but�no�procedures.�Inthis�situation�the�insurer,�vehicleowner,�and�repairer�need�todiscuss�the�considerations�todetermine�how�the�vehicle�shouldbe�repaired.

• accessibility.�Most�vehiclesare�built�starting�with�the�floorpan.�The�rest�of�the�parts�arethen�installed�around�it.�Thismakes�it�difficult�to�remove�acomplete�floor�pan�and�install�a

replacement.�This�may�requirean�entire�uniside,�the�rails,�or�theroof�to�be�removed�to�install�areplacement�floor�pan.

• special�collision�energymanagement�features.�Forexample,�the�center�of�the�floorpan�on�the�2009�Volvo�S40�isdesigned�with�a�mini-crashboxthat�collapses�to�protect�the�frontoccupants.�This�allows�the�seatsto�shift�toward�the�center�of�thevehicle�rather�than�collapsing.The�mini-crashbox�should�beinspected�for�deformation�whenanalyzing�damage�after�a�sideimpact.�The�mini-crashbox�is�partof�the�floor�pan.�The�front�floorpan�is�serviced�as�a�replacementpart.

Ford�F-150�Super�Crew

This�roof�panel�is�attached�to�the�vehicle�structureusing�laser�welds.

Roof�panels:

• are�generally�made�from�mildsteel.�However,�roof�bows�may�bemade�from�a�variety�of�stronger

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materials�to�help�strengthen�theupperbody�in�side�impacts.

• may�be�laser�welded,�spot�welded,or�bonded�to�the�roof�structure.Roofs�that�are�laser�welded�by�thevehicle�maker�are�often�replacedwith�welds,�or�a�combination�ofwelds�and�adhesives.

• may�be�fastened�to�the�roofstructure.

Some�roof�bows�are�made�from�UHSS,depending�on�the�vehicle�design,�to�helpreduce�intrusion�during�side�impacts.�Forexample,�the�roof�bow�over�the�B-pillaron�the�2011�Volkswagen�Touareg�is�madefrom�UHSS�hot-formed�steel.�On�Touaregsthat�have�the�panoramic�sliding�roof,�theglass�is�surrounded�by�a�tailor-weldedreinforcement�frame.

When�removing�the�roof,�consider�that�itmay�require:

• stationary�glass�removal.• additional�interior�trim�removal.• replacement.�Undamaged�roofpanels�may�not�be�reusable�afterthey�have�been�removed.�So�if�theroof�has�to�be�removed�to�accessexterior�panel�flanges,�a�new�roofmay�be�required.

Some�roofs�can�buckle�from�structural�damage�sincethe�unitized�structure�can�twist�and�distort�bodypanels.

Roof�panels�should�be�inspected�for:

• dents.• separation�from�the�roof�bows.• cracked�seam�sealer.• a�damaged�or�torn�vinyl�roof.Vinyl�may�be�used�on�full�vinylroofs,�landau�roofs,�convertibletops,�or�simulated�convertibletops.

• damage�to�antennas.• finish�damage.

Volvo�XC90

Roof�bows�between�the�B-pillars�may�be�made�ofUHSS�to�help�limit�intrusion.�The�roof�rail�may�besectioned�to�allow�adjacent�panel�attachment.

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Considerations�for�repairs�to�the�roofstructure�include:

• roof�bows�may�be�availableseparately.

• roof-to-roof�rail�configurations.• center�bow�may�be�made�fromUHSS�to�limit�intrusion.

When�reinstalling�the�roof,�some�vehicleshave�laser�welds�or�MIG�brazing�at�theroof-to-roof�rail�seam.�Some�vehiclemakers�recommend�grinding�the�laserweld�seam�for�removal�and�replacingthe�laser�weld�seam�with�adhesive,spot�welds,�and�GMA�(MIG)�weldswhere�the�spot�welder�will�not�reach.Audi,�Volkswagen,�Volvo,�and�Fordare�examples�of�vehicle�makers�thatrecommend�this�procedure.

The�2011�Cadillac�CTS�uses�windshieldurethane�on�the�roof�rail�area�and�GMA(MIG)�plug�welds�on�the�windshield�andbackglass�flanges.

Refer�to�the�presentation,�"Video:�SideImpact�Damage�Analysis"�for�a�video�thatshows�some�techniques�used�to�analyzedamage�from�a�side�impact.

Rear�Impact�Damage�Analysis

Ford�Mustang

The�trunk�floor�may�be�used�to�close�out�the�rearrail,�creating�a�complete�rail�structure.

Trunk�floors:

• are�generally�single�layer�mildsteel.

• may�be�part�of�the�rear�railstructure�in�that�it�contributesto�structural�integrity�of�the�railand�can�affect�how�the�rear�railcollapses.�For�example,�trunkfloors�often�close�out�three-sidedrear�rail�hat�channels.

• may�be�one-�or�two-piececonstruction.

• should�be�inspected�for�anyattaching�parts�and�damage�tothose�parts.�The�vehicle�batteryor�a�CD�/�DVD�carrier�may�belocated�in�the�trunk.

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Ford�Mustang

Floor�pan�sectioning�may�be�done�on�select�modelsdepending�on�vehicle�maker�recommendations.

When�determining�possible�repairprocedures�for�the�trunk�floor,�note�that:

• one-piece�construction�may�beable�to�be�sectioned.

• two-piece�construction�has�aseparate�trunk�floor.

• there�may�be�convolutions�andcompound�shapes�to�absorbcollision�energy.

Chrysler�Town�&�Country

This�Stow�N'�Go�tub�in�the�floor�is�used�in�theChrysler�Town�&�Country�to�hide�rear�passengerseats.

SUVs�and�minivans:

• have�a�rear�floor�pan�instead�of�atrunk.

• typically�have�large�rear�dooropenings�that�allow�easy�accessto�the�rear�floor�pan.�This�mayreduce�the�number�of�adjacentparts�that�require�removalcompared�to�a�trunk�floor.

• may�have�storage�tubs�integratedinto�the�floor.�For�example,Chrysler�minivans�have�Stow�N'Go�seating�that�requires�a�storageplace�for�the�seat�when�it�is�foldeddown.�This�storage�tub�is�bondedinto�the�floor�and,�if�damagedbeyond�repair,�is�replaced�with�aseparate�tub�that�is�bonded�withurethane�adhesive.

Volvo�XC90

The�rear�body�panel�on�the�Volvo�XC90,�herecolored�red,�is�made�of�boron-alloyed�steel.

The�rear�body�panel:

• is�beneath�the�deck�lid�or�lift�gateand�attaches�the�left�and�rightinner�quarter�panel�structures.

• may�be�made�from�multiple�steelstrengths�depending�on�vehicledesign.�For�example,�some�Volvomodels�make�rear�body�panels

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out�of�boron-alloyed�steel,�whileother�models,�such�as�the�2011Volkswagen�Jetta,�use�a�mild-strength�steel�(220�MPa).

• may�be�made�of�multiple�panelsand�serviced�as�an�assembly.

Volvo�XC90

This�rear�body�panel�on�the�Volvo�XC90�wasreplaced�at�factory�seams.

Repair�considerations�for�the�rear�bodypanel�include:

• typically�replacing�the�part�atfactory�seams.

• sectioning�may�be�an�optiondepending�on�the�vehicle�maker.

• quarter�panels�may�overlap.• attached�with�squeeze-typeresistance�spot�welds�(STRSW)and�/�or�adhesive.

Chevrolet�Malibu

The�rear�rails�on�this�Chevrolet�Malibu�allow�partialreplacement�at�factory�seams.

The�rear�rails,�together�with�thecrossmembers,�form�the�rear�underbodystructure�on�a�unibody�vehicle.�The�rearrails�also�support�the�floor�pan�and�trunkfloor.

Rear�rails:

• are�made�from�various�steelstrengths�depending�on�vehicledesign.

• may�be�closed�out�by�rear�bodypanel,�floor�pan,�and�bumperbracket.

• may�be�made�from�tailor-weldedblanks.

• may�be�available�as�complete�sub-assembly.

• may�serve�as�the�attachment�pointfor�the�trailer�hitch.

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Volvo�XC90

This�shows�the�sectioning�location�for�the�rear�rail�onthe�Volvo�XC90.

When�determining�rear�rail�repairability:

• closeout�panels�limit�applicationof�corrosion�protection.

• multiple�layers�may�be�used�at�reartorque�box�areas.

• some�rear�rails�have�crush�boxes.An�example�is�the�2011�FordFiesta.�These�are�designed�to�bolton�to�the�rear�rails.

Cutting�an�access�window�in�thetrunk�floor�to�assist�with�straightening,sectioning,�or�replacing�a�rear�rail�if�anaccess�window�is�not�specified�in�therepair�procedure�is�not�recommended.Cutting�out�a�section�of�a�part,�thenrewelding�the�removed�section�back�onthe�part�is�considered�sectioning.

Stationary�Glass

This�shows�the�windshield�on�the�Volvo�C70�(left).This�shows�the�panoramic�roof�on�the�Lincoln�MKT(right).

Types�of�stationary�glass�include:

• windshield.• backglass.• panoramic�roof�glass.• side�glass�(quarter�glass).

Stationary�glass:

• especially�the�windshield,�is�partof�the�vehicle�structure.

• contributes�to�the�strength�of�theroof�and�the�pillars.

• helps�manage�collision�energy.For�example,�in�a�front�collision,�aurethane-bonded�windshield�helpsdirect�energy�around�the�A-pillarsand�over�the�roof,�away�from�thepassenger�compartment.

• may�work�with�the�passengerairbag.�The�passenger�airbag�maybe�designed�to�deflect�off�thewindshield�during�deployment.With�this�type�of�design,�thepassenger�airbag�may�be�renderedineffective�if�the�windshield�hasbeen�installed�improperly.

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• must�be�installed�properly�byfollowing�the�proper�procedures,using�the�proper�materials,�andfollowing�the�specified�cure�times.This�is�important�for�ensuring�thatthe�structural�integrity�of�the�glassis�maintained.�Some�vehicles�mayrequire�special�urethane�adhesivefor�stationary�glass�installation.

Installing�replacement�glass,�or�re-installing�glass�that�had�to�be�removed�forrepairs:

• requires�following�properprocedures�and�productrecommendations.

• should�have�documentation�of�therepair�for�liability�purposes.

Toyota�Corolla

This�glass�was�damaged�from�the�airbag�deflectingoff�the�windshield�during�deployment.

When�checking�stationary�glass�fordamage,�look�for:

• visible�damage.�This�may�includecracks,�pits,�scratches,�and�leaks.Some�types�of�minor�damage�are

repairable�as�long�as�the�damageis�not�in�the�driver's�line�of�sight.

• damage�to�trim�and�moldings.• signs�of�water�leaks.�Moisture�atthe�interior�seams�may�indicatehidden�damage�to�the�urethaneadhesive.�Repairing�the�leak�mayrequire�removal�and�reinstallationof�the�glass.�Corrosion�on�thepinchweld�flange�is�anotherindication�of�a�water�leak.

• delamination�of�laminated�glass.Delamination�may�appear�as�whitestreaks�or�spots�and�cannot�berepaired.�If�it�is�determined�thatthe�delamination�was�pre-existing,it�should�be�communicated�to�thecustomer.

• improper�previous�installation.This�may�include�body�filler,topcoats,�or�seam�sealer�on�thepinchweld�flange.�Body�filler�andseam�sealer�should�not�be�usedunder�urethane�adhesive�becauseit�creates�a�weak�link�in�thebonding�process.�If�this�is�found,remove�any�body�filler�or�seamsealer,�prime�the�pinchweld,�andapply�the�recommended�urethaneprimer�and�urethane�adhesive.More�information�on�treatinga�corroded�pinchweld�can�befound�in�the�article�"WindshieldPinchweld�Corrosion�Repair"�inthe�May�28,�2007�issue�of�the�I-CAR�Advantage�Online.

• damage�to�the�integrated�radioantenna.

• damage�to�the�defroster�grid.Damaged�defroster�grids�may�berepairable.

• damage�to�the�interior�side�of�theglass�caused�by�mass�inertia.

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If�any�of�these�conditions�are�present,glass�replacement�may�be�necessary.

Jeep�Wrangler�Unlimited

Glass�repair�depends�on�the�extent�and�location�ofdamage.

Stationary�glass�will�often�require�removalwhen�repairing�or�replacing�adjacentpanels.�Other�considerations�for�repairingor�replacing�damaged�stationary�glassinclude:

• nonconductive�adhesive.Nonconductive�urethane�adhesiveis�required�on�some�vehicleswhere�there�are�antenna�grids,defroster�grids,�and�otherelectronic�systems�integratedinto�the�glass.�The�bus�barson�the�side�of�the�glass�oftencontact�the�adhesive,�whichdraws�power�and�weakens�thesignal.�This�is�often�the�casewith�aluminum�pinchwelds.The�conducting�current�alsocombines�with�moisture,causing�pits�and�corrosion�in�thealuminum.�Vehicles�that�requirenonconductive�adhesive�are�morecommon�with�European�vehiclessuch�as�BMW,�Mercedes-Benz,

and�Volkswagen�than�on�domesticand�Asian�vehicles.

• the�type�of�glass.�Repairs�todamaged�glass�may�depend�on�thetype�of�glass.�Only�some�minorscratches�can�be�repaired�ontempered�glass.�Minor�repairs�aredefined�as�repairs�to�scratches�thatcannot�be�felt�with�a�fingernail.These�may�be�able�to�be�buffedout.�Windshields�are�typicallymade�of�laminated�glass.�Repairsto�laminated�glass�may�include"bullseyes,"�"star�breaks,"�andsome�small�cracks.�However,repairs�are�only�possible�if�thedamage�is�contained�to�the�outerlaminate�or�if�the�damage�is�notlocated�in�the�driver's�direct�view.

• fire�damage.�Stationary�glass�thathas�been�exposed�to�fire�mayrequire�replacement.�Excessiveheat�may�weaken�the�urethaneadhesive�that�holds�the�glass�inplace.�The�inner�plastic�laminatemay�also�be�weakened�whenexposed�to�excessive�heat.Delamination�may�cause�largepieces�of�glass�to�come�looseand�injure�the�occupants�duringanother�collision.�Cracks�orwarpage�of�the�glass�may�indicatethat�it�has�been�exposed�toexcessive�heat.

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Volvo�XC60

The�label,�or�bug,�on�the�glass�will�provide�anindication�on�what�type�of�glass�needs�to�be�installed(left).�Vehicle�options�may�dictate�what�type�of�glassshould�be�installed�(right).

Not�all�windshields�are�the�same�for�eachmodel�of�vehicle.�This�requires�payingspecific�attention�to�the�vehicle�optionswhen�determining�which�type�of�glassto�order.�Options�that�may�affect�whichwindshield�is�ordered�include:

• head-up�displays�(HUD).�Vehiclesequipped�with�HUD�may�requirea�special�type�of�windshield.Installing�the�wrong�type�ofwindshield�may�result�in�a�doubleor�distorted�HUD�image.�A�glasssurface�on�top�of�the�dash�panel�orlabeled�switches�and�controls�maybe�indications�that�the�vehicle�isequipped�with�a�HUD.

• an�acoustic�windshield.�This�typeof�windshield�is�used�on�the�2011Honda�Odyssey�to�help�reduce�theamount�of�wind�noise.

• a�rain�detection�sensor.• a�lane�departure�warning�sensor.• attention�assist.• window�tint.�It�may�be�required�toidentify�between�aftermarket�andfactory�tinting.

• a�heated�windshield.• heated�wipers.

Each�of�these�systems�may�requirea�unique�windshield�design�toaccommodate�the�vehicle�options.�Thismay�include�glass�construction�or�fritdesign.�The�frit�is�the�black�band�aroundthe�perimeter�of�the�stationary�glass.�Thefrit�helps�prevent�ultraviolet�rays�fromdeteriorating�the�urethane�adhesive.

Chevrolet�HHR

Urethane�glass�adhesive�is�being�applied�to�thepinchweld�on�this�Chevrolet�HHR.

Glass�replacement�is�often�a�subletoperation�that�is�done�by�professionalglass�installers.�Following�installation,the�vehicle�must�sit�stationary�while�theglass�adhesive�cures.�The�adhesive�mustreach�full�strength�before�it�is�allowedto�leave�the�repair�facility.�This�ensuresthe�integrity�of�the�upper�structure�in�theevent�of�a�rollover,�and�may�be�used�todeflect�passenger�side�airbags�during�adeployment.

This�amount�of�time�depends�on�thetemperature�and�humidity�levels,�butgenerally�takes�several�hours.�This�isimportant�to�note�when�informing�thecustomer�on�when�they�can�expect�theirvehicle�repairs�to�be�complete.

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Refer�to�the�presentation,�"Video:Laminated�Glass�Damage�Analysis�-�Part1"�that�raises�a�question�about�whetherspecific�damage�to�the�vehicle�windshieldis�repairable.

Refer�to�the�presentation,�"Video:Laminated�Glass�Damage�Analysis�-Part�2"�which�provides�the�answer�aboutwhether�damage�to�the�windshield�isrepairable.

Body-Over-Frame�Vehicles

Jeep�Wrangler

This�is�the�complete�frame�for�a�Jeep�Wrangler.

Vehicle�frames�are:

• designed�to�manage�collisionenergy.

• made�of�mild�steel,�HSS,�and�/�orUHSS.

Nissan�Titan

Notice�the�dimpled�crush�initiators�on�the�front�railof�the�Nissan�Titan.

Collision�energy�management�principlesfor�frames�is�similar�to�a�unibody�structurein�that�the�frame�has:

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• collapse�and�crush�zones�in�thefront�rails.

• kickup�or�offset�areas.• elongated�holes�or�slots.• varying�part�shape.• reinforcements�or�lateral�stiffeners.

Each�of�these�allows�the�frame�to�deformat�specific�locations�to�absorb�or�transfercollision�energy.

Bends,�such�as�this,�may�not�be�repairable�due�tothe�thickness�and�strength�of�the�metal�(left).�Stresscracks�such�as�this�may�be�repaired�depending�onhow�they�were�formed�(right).

When�inspecting�the�frame,�check�for:

• bends�in�the�structure.�Dependingon�the�thickness�and�strength�ofthe�metal,�bends�may�or�may�notbe�repairable.�Heat�use�whenstraightening�bends�is�generallylimited.

• kinks,�which�are�not�repairable.• cracks.�These�may�be�repairable,but�are�limited�to�stress�cracks.This�may�require�welding�areinforcement�on�the�front�orbackside�of�the�crack.�Whenrepairing�cracks�in�a�frame,reinforcements�should�NOT�beused�in�collapse�zones.

Frame�cracks�that�should�not�be�repairedinclude�those:

• near�the�steering�box�area.• near�a�suspension�mounting�area.• on�the�top�or�bottom�flange�ona�frame�with�an�open�C-channeldesign.

• caused�by�straightening�an�areathat�was�previously�kinked.

Damage�related�to�trailer�hitches�is�acommon�occurrence�on�full-frames.�Oftenthe�impact�pushes�the�frame�downward,bending�at�a�point�near�the�end�of�thetrailer�hitch.

Crossmembers�with�this�type�of�damage�arereplaced.

Other�items�that�must�be�inspected�onfull-frames�include:

• damaged�cab�mounts.�Inspect�thecab�mounts�for�damage�due�toinertia.

• bent�crossmembers.�Generally,damaged�crossmembers�are�nota�serviceable�part�unless�they�arepart�of�an�assembly.�However,Toyota�has�many�vehicles�where

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crossmembers�are�a�serviceablepart.

• control�arm�/�suspension�mountingbrackets.�These�are�difficult�tostraighten�while�ensuring�that�theydo�not�deform�due�to�repeatedstress.�Depending�on�replacementrecommendations,�parts�may�beavailable,�or�the�frame�or�framesection�may�need�to�be�replaced.

• steering�mounting�brackets.

Damaged�bumper�mounting�bracketsshould�not�be�straightened.�Theseare�usually�replaced�using�a�bolt-onreplacement�bracket.

Ford�Expedition

Some�vehicle�makers�have�front�or�rear�framemodules�that�can�be�replaced�if�damaged.

Partial�replacement�at�factory�seams�maybe�done�on�full-frames�depending�onvehicle�maker�recommendations.�Piecesof�the�frame�that�are�often�replaced�mayinclude:

• frame�rail�ends�that�are�designedto�crush�in�a�frontal�collision.

• a�crush�box,�also�designed�tocrush�in�a�frontal�collision.�Crushboxes�are�sacrificial�parts�designedto�collapse,�preventing�damage

from�radiating�deeper�into�thestructure.

• front�or�rear�frame�modules.�Forexample,�the�2011�ChevroletSilverado�has�a�replacementrear�frame�assembly�service�partavailable.�The�procedure�usesa�factory�seam�for�rear�modulereplacement.

Examples�of�sectioning�or�partialreplacement�on�full-frames�include:

• the�front�rail�end�on�the�2011�FordExpedition,�and�the�2011�FordCrown�Victoria�/�Lincoln�TownCar.

• a�sectioning�procedure�behind�thefront�crossmember�on�the�2007Ford�F-250�and�F-350.

• a�frame�sectioning�procedurefor�the�2011�Cadillac�Escalade.The�procedure�includes�the�front400�mm�of�the�frame�rail,�whichincludes�the�front�crossmember.

Ford�F-150

This�is�a�body�mount�used�to�bolt�the�unitizedstructure�to�the�frame�(left).�This�is�a�unitizedstructure�being�lowered�onto�a�repaired�frameassembly�(right).

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The�unitized�structure�that�is�bolted�tothe�frame�is�repaired�similar�to�a�unibodyvehicle.�Pillars,�rocker�panels,�and�frontupper�rails�must�be�repaired�accordingto�the�vehicle�service�information,�takinginto�consideration�the�different�types�ofconstruction�materials�and�part�design.

When�analyzing�the�damage:

• note�that�damage,�similar�to�theunibody�structure,�can�transferenergy�and�damage�to�areas�awayfrom�the�direct�impact.

• distortions�to�the�frame�can�alsocause�stresses�to�the�unitizedstructure.�Sometimes,�whenthe�frame�is�returned�to�factorydimensions,�the�stress�on�theattached�unitized�structure�isrelieved�and�the�measurementsreturn�to�specification,�however,it�is�important�to�monitor�bothupperbody�and�frame�dimensionsat�the�same�time.

Ford�F-150

Inconsistent�cab-to-bed�gaps�may�be�a�visualindication�of�frame�damage.

On�full-frame�vehicles,�the�frameassembly�may�not�have�visual�damage,but�there�are�several�indicators�thatstructural�damage�has�occurred,including:

• shifted�body�mounts.�The�radiatorcore�support�on�a�full-framevehicle�is�generally�bolted�to�theframe�assembly.�It�is�common�forthe�radiator�core�support�to�slideduring�a�frontal�impact,�causingthe�hood-to-fender�gaps�to�beinconsistent.�Generally,�the�gapwill�be�tight�on�one�side�and�wideon�the�other.

• panel�misalignment.�An�indicatorof�a�diamond�condition�isinconsistent�gaps�between�the�caband�the�truck�bed�on�a�pickuptruck.�One�side�will�generally�bewider�than�the�other�side.

• wheel�position�in�the�wheelopening.

When�repairing�full-frame�vehicles,�theframe�is�often�pulled�separately�from�theunitized�structure.�This�requires�removingthe�cab�mount�bolts�to�allow�the�twostructures�to�move�independently.

Module�Wrap-Up

Topics�that�were�covered�in�this�moduleincluded:

• general�repair�considerations�forstructural�parts.

• front�structural�parts�and�commontechniques�for�analyzing�damagefrom�front�impacts.

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• side�structural�parts�and�commontechniques�for�analyzing�damagefrom�side�impacts.

• rear�structural�parts�and�commontechniques�for�analyzing�damagefrom�rear�impacts.

• specific�damage�to�determine�ifstructural�glass�should�be�repairedor�replaced.

• common�types�of�damage�thatcan�occur�to�body-over-framevehicles�and�determining�if�it�canbe�repaired.