institute of production technology and forming - machines · pdf file ·...

ED_BE 1

Engineering Council

Institute of Institute of ProductionProduction Technology Technology and and FormingForming -- Machines Machines

Univ.-Prof. Dr.-Ing. Bernd Engel

ED_BE 2

Engineering Council

Engineering Engineering CouncilCouncil

07th April 2004

ED_BE 3

Engineering CouncilInstitute of Institute of ProductionProduction TechnologyTechnology

and and FormingForming MachinesMachines

Demands of Automotive Industry

New Materials (High Strength Steel)

Demands to Forming Technology

Bending and Hydroforming

ED_BE 4

Engineering CouncilDemands of Automotive Industry

BMW E60, Quelle: ATZ/MTZ extra August 2003 D 58922

Hybrid Body Structure

New Conceptswith Profiles

Total Simulation: From Sheet to Crash

BMW 5-Series Body In White with High-Strength Steel Components

High-Strength Steel SteelAluminum

ED_BE 5

Engineering Council

Alloys for the Body In White of the new 5-Series


Aluminium Add-onParts new 5 Series





ED_BE 6

Engineering Council


Production Processes


Extrusion ProfileCastingHydroformingRollforming




ED_BE 7

Engineering Council

VDI-Nachrichten 12. September 2003 Nr. 37

New Steel Body





ED_BE 8

Engineering Council

ULSAB Report

Ultra Light Steel Auto Body





ED_BE 9

Engineering Council

Atlas – Space Frame





ED_BE 10

Engineering Council

Crash Simulation based on different Inputs (1)

Material propertiesfromTensile-Testof Sheet

Assumption: Same

properties forYield

Strength, Thickness

over the Part





Material properties

afterForming-

Processesof Part.

Variousproperties

over the Part depend on Forming -

Processes and Hardening -

Effects.

Forming-Simulation

TensileTest

ED_BE 11

Engineering Council

Basewith Mapping

Crash Simulation based on different Inputs (2)

Base Mapping


Crash-Simulation

Mapping Data from all Forming -Processes




ED_BE 12

Engineering Council

Base

with Mapping

Mapping Data for Crash-Simulation

withoutMapping

with Mapping

higher local Plastifications


Increasedwall-thickness




ED_BE 13

Engineering Council

Use of Hardening-Effect

New Bending Concepts

Profile –Hydroforming

Sheet –Hydroforming

Mapping Data from different Forming-Technologies


True Strain ϕ [-]

Stre

ss [M

Pa]

Stamping Hydroforming

ED_BE 14

Engineering Council

0

10

20

30

40

50

60

70

0 400 600 1000200 800 1200Elastic Limit (MPa)

Elon

gatio

nat

Fra

ctur

e(%

)

Soft Deep Draw Steel

Martensite SteelTRIP-SteelDP-/MP-Steel

CMnHigh-Strength Micro Alloyed Steel

BH-SteelHigh-Strength IF-Steel

IF-Steel

Isotropic Steel

LSS< 210 MPa

UHSS> 550 MPa

HSS210 - 550 MPa

New Materials: Chance and Challenge

Material Properties

ReducedFormability


ED_BE 15

Engineering Council

New Materials: Chance and Challenge

Material Properties

ReducedFormability


Form Limit Curve

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

-0,4 -0,3 -0,2 -0,1 0 0,1 0,2 0,3 0,4 0,5 0,6

AlMgSi05 DP600 St14

Flow-Curve

0

100

200

300

400

500

600

700

800

900

0 0,2 0,4 0,6 0,8 1 1,2

Strain

Stre

ss [N

/Mpa

]

Use of new Materials: Hardening - Effect via Forming Limit

Stre

ss [M

Pa]

True Strain ϕ [-]Minor Strain ϕ

Maj

orS

trainϕ

ED_BE 16

Engineering Council





Classification of Hydroforming

Forming with Fluids

Hydroforming of hollow profiles

Sheet Hydroforming

HydroformingDeep drawingwith Fluids

Quelle: VDI Richtlinie 3146, Blatt 1Prospekt VIA Formtec

ED_BE 17

Engineering Council

Hydroforming: Complete Process


Hydroforming - Process

Tube-Forming Bending Die Closing Hydroforming Part properties





ED_BE 18

Engineering Council

Hydroforming wthaxial Feed

Limited Lengthfor Expanding-

Area

Hydroforming wthaxial Feed

Limited Lengthfor Expanding-

Area

Profile Hydroforming

BendingLimited RadiiBending

Limited RadiiLimitation forHydroforming

HydroformingCalibration

Limited Corner-Radii

HydroformingCalibration

Limited Corner-Radii

HydroformingLimited

Circumference

HydroformingLimited

Circumference

JoiningAlternative Joining

Methods

JoiningAlternative Joining

Methods






ED_BE 19

Engineering Council

R

Tendency: Tubes for Structural - Elements inrease to a Ratio greater than 90. Ratio: Outer-Diameter to Wall - Thickness

Bending – forming limits


Outer ∅ of the Tube

Wall Thickness of the Tube

Ben

ding

Rad

ius

Out

er∅

of th

eTu

be

Bending not possible

Mandrel with a couple of Balls

Mandrel with twoBalls

Mandrel withone Ball

No Mandrelnecessary

Limitation of small Radii

as a result of Buckling

Limitation of small Radii

as a result of Buckling





ED_BE 20

Engineering Council

Bending: Forming - Limit: minimum Radius

Flexible Mandrel to provide Buckling and enlarge Forming-Limit


Thyssen Folie - Dornm

Aktiver Faltenglätter Triboprüfstand

Ball-Mandrel StrainFlexible Mandrel





ED_BE 21

Engineering Council

Bending: Forming - Limits


Measurement-Boxfor Normal - Forces and Friction - Forces

Active Wiper DieLimitation of bigRadii as a Resultof limited Tool-

Size

Limitation of bigRadii as a Resultof limited Tool-

Size





ED_BE 22

Engineering Council

Hydroforming Limits restricted through Bending - Limits





Bending-Line places the Cross - Sections

Position 1

Position 2

ED_BE 23

Engineering CouncilBending and Hydroforming




Positioning in Hydroforming Die – Position 1: no Cracks


ED_BE 24





Positioning in Hydroforming Die – Position 2: with Cracks


ED_BE 25

Engineering Council

Bending – 3 Rollers Bending





Feed

Roll 2

Roll 1

Positioning X

Positioning Y

Bending Roll

Bending Radii

Positioning Y

Pos

ition

ing

X

Collision with Roll 1

Collision with Roll 2

ED_BE 26

Engineering Council

Hydroforming – restricted Design of Radii


Internal pressure to form out inner radii

0 0,1 0,2 0,3 0,4 0,5 0,6

s / r [-]

0500

100015002000250030003500400045005000

p i[b

ar]

Rm=200N/mm2

Rm=400N/mm2

Rm=600N/mm2

Rm=300N/mm2

Rm=500N/mm2

Rm=700N/mm2

Tendency: High – Strength - Steel raises the internal Pressure




ED_BE 27





Sheet Hydroforming

ED_BE 28


Tendency: Big Sheets increases Clamping Force and Cycle Time




Required Pressure: 400 bar

Required Pressure: 150 bar

Required local Pressure over the whole Part

ED_BE 29

Engineering Council

Jet

Lance

Sheet





Future Methods to focus the Pressure

ED_BE 30

Engineering Council

Variant Pressure Direction Tool

inside notnecessary

inside partial

inside complete





Classification of incremental Hydroforming

ED_BE 31

Engineering Council

Variant Pressure Direction Tool

outside

outside partial

outside complete

Classification of incremental Hydroforming





notnecessary

ED_BE 32





Pulse Hydroforming – Pressure Distribution

Pressure build

up after Unload

of a Condenser

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