ansys ncode designlife™ for 13.0 ansys® workbench™ beach... · 1 © 2011 ansys, inc. 8/29/11...

© 2011 ANSYS, Inc. 8/29/111

ANSYS nCode DesignLife™

for 13.0 ANSYS® Workbench™

Jeff MentleyHBM-nCode

© 2011 ANSYS, Inc. 8/29/112

Agenda

IntroductionWhat is Fatigue and Why is it importantApproaches for FatigueANSYS nCode DesignLife overviewWhat is new for ANSYS 13.0 DesignLife SP1Questions

© 2011 ANSYS, Inc. 8/29/113

ANSYS® nCode DesignLife™

Integrated within ANSYS Workbench 13 to provide a leading solution for advanced fatigue analysis.

© 2011 ANSYS, Inc. 8/29/114

What is Fatigue?Fatigue is:

Fai lure under a repeat ed or ot herw ise var y ing load w hic h never reac hes a level suf f i c ient t o c ause fa i lu re in a s ing le appl ic at ion.

T he in i t iat ion and g row t h of a c rac k , or g row t h o f a pre-ex is t ing defec t , unt i l it reac hes a c r i t ic a l s ize.

The progressive and localized structural damage that occurs when a material is subjected to cyclic loading.

Strain

Str

ess

Time

Str

ess

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Slide 5

Early Failures

1808 Trevithick's “Catch-me-who-can”

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Slide 6

Present Day Fatigue Failure

– Hit br idge p i l lar - 100 k i l led

– Ear ly w heel des ign c aused v ib rat ions

– New w heel des ign– Based upon st ree t c ar des ign– Not t es t ed at h igh speed

before ser v ic e– Com plet e prot ot ypes never

t es t ed– Crash f ind ings

– Caused by c rac k in w heel– Dynam ic , repet i t ive forc es

had not been ac c ount ed for in des ign

– Design lac ked an adequat e m arg in o f safe t y

1999 – ICE high-speed trail derailed at Eschede, Germany

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Why is it Important ?

Why do we need to do Fatigue Analysis?• “...Between 80 - 90% of all structural failures

occur through a fatigue mechanism…”• “...The estimated annual cost of fracture and

fatigue to the US was 4.4% of GDP…”

“The Economic Effects of

Fracture in the United States,” National

Bureau of Standards, U.S. Department of

Commerce, Gaithersburg, MD, Special

Publication 647-2, 1983.

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Fatigue Analysis Process

Fatigue is a statistical, not deterministic, phenomenon.

• Stress-life• Strain-life• Crack growth

Life

Loading Environment

Geometry

Material Properties

Post-processing optimization

Fatigue Analysis

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Fatigue Analysis: Stress-Life (SN)

SN is also known as “High Cycle Fatigue” or “Nominal Stress Approach”

Elastic stress history used to determine life

May be applied to either material or component

Used extensively for welded joints and non-metallics

Suitable for lives greater than 1e4 cycles

Well established, Familiar, Large amount of material data available, Simple loadings can be analyzed as a hand calc.

Wöhler circa 1850

104 105 106Cycles, N

Str

ess

, ce

ntn

ers

/zo

ll2

400

200

600

800

Smooth shoulder

Sharp shoulder

© 2011 ANSYS, Inc. 8/29/1110

EN is also known as “Low Cycle Fatigue”, “Crack Initiation” or “Local Strain Approach”

Elasto-plastic strain history used to determine life

Local plasticity can be estimated from fully elastic FE analysis or computed directly in ANSYS

Suitable for low and high cycle fatigue

Cycle counting and plasticity corrections difficult to do by hand.

Fatigue Analysis: Strain-Life (EN)

ε

N

Plastic (Low CycleFatigue Line)

Elastic (High CycleFatigue Line)

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Fatigue Analysis: Crack Growth

Crack growth known as crack propagation, or fracture mechanics

Predicts cycle by cycle crack growth

Used in aerospace Damage Tolerance analysis

Determine impact of known or suspected flaws

Crack

© 2011 ANSYS, Inc. 8/29/1112

Materials

Stresses

Loads

Mechanical

Engineering Data

DesignLife

ANSYS® nCode DesignLife

ANSYS™ Workbench®

© 2011 ANSYS, Inc. 8/29/1113

ANSYS® nCode DesignLife™

– nCode OEM Par t nersh ip– nCode Des ignLi fe

– Advanc ed Fat igue Analys is

– Proc ess Or ient at ion– Ease o f Use

– Wor k benc h In t eg rat ion– DesignLi fe Syst em s– Design Param et ers– Mat er ia l l ibrar y

© 2011 ANSYS, Inc. 8/29/1114

ANSYS® nCode DesignLife™ - FeaturesStreamlining the Virtual

Engineering Process

– Powerful Fatigue Analysis Technology

– Integrated Reporting and Process Encapsulation

– Fast, Expandable, and Scalable

© 2011 ANSYS, Inc. 8/29/1115

ANSYS® nCode DesignLife™ - Features

Intuitive and easy to use software for per for m ing fat igue anal ys is o f f in i t e e lem ent m odels .

Efficiently analyze large f in i t e e lem ent m odels and c om plet e usage sc hedules.

Wide range of fatigue analysis capabilities inc lud ing s t ress-l i fe , s t ra in-l i fe , m ul t i -ax ia l, w eld analys is, v i r t ua l shaker t ab le , and m ore.

Single environment for bot h Test and CAE dat a.

Ex t ens ive material database

© 2011 ANSYS, Inc. 8/29/1116

ANSYS® nCode DesignLife™ - Capabilities

–St ra in-L i fe (aut om at ed m ul t i -ax ia l c or rec t ions)–St ress-L i fe (s ing le , m ul t i -c ur ve, Haigh d iag ram s)–Crac k Grow t h (LEFM)–Seam w elds and spot w elds–High t em perat ure fat igue–Vibrat ion fat igue (shaker s im ulat ion)–Vir t ual St ra in gage–Com plet e dut y c yc les / f l ight spec t r um s–Mult ip le r uns in a s ing le ana lys is–Mult i -proc essor enabled for fast resul t s

Fin i t e Elem ent resu l t s suppor t ed– St at ic (l inear

super pos i t ion)– Trans ient – Modal– Frequenc y Response– Linear & Non-l inear

Fin i t e Elem ent so lvers suppor t ed

– ANSYS– Abaqus– Nast ran– LS-Dyna

ANSYS nCode DesignLife has an extensive scope of fatigue capabilities…

© 2011 ANSYS, Inc. 8/29/1117

ANSYS® nCode DesignLife™ - Benefits

– Perfor m v i r t ua l durabi l i t y assessm ent up f ront t o reduc e re l ianc e on physic a l t es t and avoid c ost l y des ign and t ool ing c hanges

– Perfor m sm ar t er and qu ic k er phys ic a l t est s by s im ulat ing f i r s t

– Design durabi l i t y in t o your produc t s and reduc e w ar rant y c la im s

– St andar dize analys is proc esses t o im prove c onsis t enc y and qual i t y

– Aut om at e proc esses t o bet t er ut i l i ze engineers ’ t im e and w or k load

– Assess m ore design opt ions, c onsider m ore real is t ic load ing c ondi t ions and m ore c onf ident l y reduc e c ost and w e ight

© 2011 ANSYS, Inc. 8/29/1118

ANSYS® 13 nCode DesignLife™ SP1

– Support for Named Selections– New state engine to manage DesignLife system

updates– DesignLife processes saved with results– FKM mean stress with multicurve SN– Material map import deactivate– Seam weld enhancements– BS7608 and Eurocode 3 weld analysis

© 2011 ANSYS, Inc. 8/29/1119

Questions

ANSYS ® nCode DesignLife™

© 2011 ANSYS, Inc. 8/29/1120

Thank you!

Jeff Mentley

HBM - nCode

Tel: +1.248.945.4368

jeff.mentley@ncode.com

Ray Browell

ANSYS, Inc.

Tel: +1.724.514.3070 Ray.Browell@ansys.com

ANSYS ® nCode DesignLife™