Abacus Fatigue Calc

V E R S I O N 6 . 1

ABAQUS

6

ABAQUS/SafeV E R S I O N 6 . 2

ABAQUS/Safe V E R S I O N 6 . 2

Introduction

ABAQUS/Safe is the fatiguepostprocessing module in ABAQUS. Ithas been developed by Hibbitt, Karlsson& Sorensen, Inc., based on technologysupplied by Safe Technology Ltd.

ABAQUS/Safe interfaces to ABAQUSoutput database (.odb) files and usesstate-of-the-art techniques to determinethe fatigue life of a component.

ABAQUS/Safe takes stress or strainresults for different loading conditionsfrom ABAQUS analyses, combines themwith the time variations of the loading,and uses cyclic material data to predictthe life of the component. The resultingdamage and life results can then beplotted using ABAQUS/CAE orABAQUS/Viewer.

The functionality of ABAQUS/Safecomplements the fracture mechanicscapabilities of ABAQUS/Standard,which can be used to investigate thebehavior of a cracked component.

P R O D U C T O V E R V I E W

The ABAQUS/Safe user interface.

Hibbitt, Karlsson & Sorensen, Inc. 1

F E A T U R E S

Fatigue Analysis

• Uniaxial analysis using stress lifecurves—Goodman, Gerber, or no meanstress correction.

• Uniaxial analysis using strain lifecurves—Morrow, Smith-Watson-Topper, or no mean stress correction.

• Biaxial fatigue analysis using localstress-strain analysis.

- Maximum shear strain.- Maximum direct strain.- Brown-Miller combined shear and- normal strain.

• Statistical analysis: statistical variabilityin loading and materials data can becombined to provide probability ofsurvival analysis.

• A critical plane procedure is used tocalculate the orientation of the mostdamaged plane at each node.

• Von Mises stress, Haigh diagrams, cycleand damage histograms, orientation ofcritical plane, biaxiality.

• Analysis of welded structures usingstress-life data from BS7608.

• Modeling gray cast iron using anincremental damage procedure.

• A rainflow counting algorithm is usedto extract fatigue cycles. This algorithmis integrated with a cyclic stress-strainconversion (a biaxial Neuber’s rule) toconvert elastic stresses from ABAQUSto elastic-plastic stresses, usingmaterial memory.

• The stress history at each node isdetermined from the stresses stored inthe ABAQUS output database and theloading sequence. A stressconcentration factor and scale factorcan be applied.

• Fatigue evaluation can be performedfor the whole model or only forspecified element sets.

Component Loading

• Load histories The elastic stressesfor unit load cases in each directionare calculated. These stresses aremultiplied by the load history ineach direction and then added toprovide a stress history for thecombined loading.

• Sequence of results For example,ABAQUS is used to analyze anengine through three rotations ofthe crankshaft, with data output forevery five degrees of rotation ofthe crankshaft. ABAQUS/Safeanalyzes this sequence of resultsto determine the fatigue life at eachnode. Additional scale factors andrepeat counts can be applied.

• Block loading sequences Stresses fromtwo sets of loads are calculated in twoABAQUS steps. A block loadingsequence could then be defined as1000 cycles of the stresses from Step 1scaled by factors of 0.1 to 1.0, followedby 1000 cycles of the stresses fromStep 2 scaled by factors of −1.0 to 2.0.

• Complex load spectrum The ability todefine complex spectra and to mixspectra and data sequences with scalefactors and repeat counts.


Material Data

A database of fatigue data for manycommon materials is provided withABAQUS/Safe. The database can beextended and modified by the user toadd customer-specific materials.

Test reports and background datacan be used to define materials inthe database, and material data canbe plotted.

Additional Factors

• Initial residual stress can be included: thiscan be a single value or a data set ofelastic FEA or elastic-plastic FEA stressesfrom a modeling process (e.g., pressforming and springback).

• Temperature-dependent fatigue datacan be used, in which case the nodaltemperatures calculated by ABAQUSare used to determine the appropriatefatigue data.

• Effects of surface finish can be includedfor all or part of the component. Thedifference in fatigue life for machinedand as-forged surfaces can, therefore,be evaluated.

• Notch sensitivity effects can beincluded. These effects are importantfor cast irons, some aluminum alloys,and lower strength steels.

• Different material data or surface finishcorrections can be specified for eachelement set in the model (for example,to allow for machined and as-forgedsurfaces in the same model).

The ABAQUS/Safe materials database.

Hibbitt, Karlsson & Sorensen, Inc.

Output

Once the fatigue analysis is complete,fatigue data are written either to theoriginal output database or to a newoutput database. Fatigue life is providedat each node, expressed as the numberof repeats of the defined loading.

A design life can be specified. In thiscase ABAQUS/Safe predicts the factorthat must be applied to the stressesat each node to achieve the specifieddesign life.

You can display the results of thefatigue analysis using ABAQUS/Vieweror ABAQUS/CAE.

3

Contour of log of lives at nodes.

Hardware &Performance

Hardware Compatibility

ABAQUS/Safe Version 6.2 requiresinstallation of ABAQUS/StandardVersion 6.2 or later. ABAQUS/Safeis available on the followingengineering workstations:

• HP-UX 10.20, HP-UX 11.0

• SGI IRIX 6.5

• Sun Solaris 2.7 (7.0)

• Windows NT 4.0

Problem Size & Performance

ABAQUS/Safe has no built-in limits onproblem size. Smaller problems runentirely in main memory. Buffering tosecondary storage occurs automaticallyas the problem size increases.


Documentation

The ABAQUS/Safe User’s Manual isavailable in print and online. It explainsin detail how to use ABAQUS/Safe.Theoretical background to fatigueanalysis is contained in the ModernMetal Fatigue Analysis manualavailable from HKS.

For installation information, see theABAQUS Site Guide.

Training & Support

ABAQUS/Safe is supported by HKS’sworldwide network of offices.

The training courses for ABAQUS/Safecover the fatigue analysis methods usedby ABAQUS/Safe and provide “hands-on” training on program usage.

Hibbitt, Karlsson & Sorensen, Inc. 5

ABAQUS online documentation permitsthe user to electronically search throughmanuals for relevant topics.

Hibbitt, Karlsson & Sorensen, Inc.5

Copyright 2001 Hibbitt, Karlsson & Sorensen, Inc. MAR_DES_V62_SFE

ARGENTINAKB Engineering S.R.L.Florida 274Piso 3, Oficina 371005 Buenos Airesphone (54) 11 4393 8444fax (54) 11 4326 2424e-mail [email protected]

AUSTRAL IAWorley FEA (A Division of Worley Limited)Level 17, 300 Flinders StreetMelbourne, Vic 3000phone (61) 3 9280 2834fax (61) 3 9205 0573e-mail [email protected]

AUSTRIAVOEST-ALPINE STAHL LINZ GmbHDepartment B3EPostfach 3A-4031 Linz phone (43) 732 6585 9919fax (43) 732 6980 4338e-mail [email protected]

BENELUXABAQUS Benelux BVHuizermaatweg 5761276 LN HuizenThe Netherlandsphone (31) 35 52 58 424fax (31) 35 52 44 257e-mail [email protected]

CHINAAdvanced Finite Element ServicesDepartment of Engineering MechanicsTsinghua University Beijing 100084, P. R. Chinaphone (86) 10 62783986fax (86) 10 62783986e-mail [email protected]

EUROPEAbaqus EuropeGaetano Martinolaan 95PO Box 16376201 BP MaastrichtThe Netherlandsphone (31) 43 356 6906fax (31) 43 356 6908e-mail [email protected]

FRANCEABAQUS Software, s.a.r.l.7 rue Jean Mermoz78000 Versaillesphone (33) 1 39 24 15 40fax (33) 1 39 24 15 45e-mail [email protected]

GERMANYABACOM Software GmbHTheaterstraße 3032D-52062 Aachenphone (49) 241 474010fax (49) 241 4090963e-mail [email protected]

IND IAABAQUS Engineering Analysis Solutions (Pvt.) Ltd.3M, Prince Arcade22-A, Cathedral RoadChennai, 600 086phone (91) 44 8114624fax (91) 44 8115087e-mail [email protected]

Hibbitt, Karlsson & Sorensen, Inc. e-mail [email protected] [email protected] www.abaqus.com

1080 Main Street Pawtucket, RI 02860-4847 USA phone 401 727 4200 fax 401 727 4208

I TALYHibbitt, Karlsson & Sorensen Italia, S.R.L.Viale Certosa, 120149 Milanophone (39) 02 3921 1211fax (39) 02 3921 1210e-mail [email protected]

JAPANHibbitt, Karlsson & Sorensen, Inc.3rd Floor, Akasaka Nihon Building5-24, Akasaka 9-chomeMinato-kuTokyo, 107-0052phone (81) 3 5474 5817fax (81) 3 5474 5818e-mail [email protected]

Hibbitt, Karlsson & Sorensen, Inc.2nd Floor, Ohmori Notock Building6-10, Edobori 1-chomeNishi-kuOsaka, 550-0002phone (81) 6 4803 5020fax (81) 6 4803 5021e-mail [email protected]

KOREAHibbitt, Karlsson & Sorensen Korea, Inc.Suite 306, Sambo Building13-2 Yoido-Dong, Youngdeungpo-kuSeoul, 150-010phone (82) 2 785 6707/8fax (82) 2 785 6709e-mail [email protected]

MALAYSIAWorley Advanced Analysis16B Damai Komplex Jalan Lumut50400 Kuala Lumpurphone (60) 3 40412122fax (60) 3 40412322e-mail [email protected]

NEW ZEALANDMatrix Applied Computing Ltd.Postal: PO Box 56-316AucklandCourier: Unit 2-5, 72 Dominion RoadMt. Eden, Aucklandphone (64) 9 623 1223fax (64) 9 623 1134e-mail [email protected]

POLANDBudSoft Sp. z o.o.61-807 Poznan Sw. Marcin 58/64phone (48) 61 852 31 19fax (48) 61 852 31 19e-mail [email protected]

SINGAPOREWorley Advanced Analysis491B River Valley Road#09-01 Valley PointSingapore, 248373phone (65) 735 8444fax (65) 735 7444e-mail [email protected]

SOUTH AFR ICAFinite Element Analysis Services (Pty) Ltd.Suite 20-303C, The WaverleyWyecroft RoadMowbray 7700phone (27) 21 448 7608fax (27) 21 448 7679e-mail [email protected]

SPAINPrincipia Ingenieros Consultores, S.A.Velázquez, 94E-28006 Madridphone (34) 91 209 1482fax (34) 91 575 1026e-mail [email protected]

SWEDENFEM-Tech ABPilgatan 8SE-721 30 Västeråsphone (46) 21 12 64 10fax (46) 21 18 12 44e-mail [email protected]

TAIWANAPIC7th Floor, 131 Sung Chiang RoadTaipei, 10428phone (886) 2 25083066fax (886) 2 25077185e-mail [email protected]

UNITED K INGDOMHibbitt, Karlsson & Sorensen (UK) Ltd.The Genesis CentreScience Park South, BirchwoodWarrington, Cheshire WA3 7BHphone (44) 1 925 810166fax (44) 1 925 810178e-mail [email protected]

UNITED STATESABAQUS Solutions Erie3601 Green Road, Suite 316Beachwood, OH 44122phone (1) 216 378 1070fax (1) 216 378 1072e-mail [email protected]

ABAQUS Solutions Northeast, LLCSummit Office Park, West Building300 Centerville Road, Suite 209WWarwick, RI 02886-0201phone (1) 401 739 3637fax (1) 401 739 3302e-mail [email protected]

ABAQUS Solutions Rocky Mountains2894 Hughs DriveErie, CO 80516phone (1) 303 664-5444fax (1) 303 664-5445e-mail [email protected]

ABAQUS South Central3700 Forums Drive, Suite 101Flower Mound, TX 75028phone (1) 214 513 1600fax (1) 214 513 1700e-mail [email protected]

AC Engineering, Inc.1440 Innovation PlaceWest Lafayette, IN 47906-1000phone (1) 765 497 1373fax (1) 765 497 4444e-mail [email protected]

Hibbitt, Karlsson & Sorensen (Michigan), Inc.14500 Sheldon Road, Suite 160Plymouth, MI 48170-2408phone (1) 734 451 0217fax (1) 734 451 0458e-mail [email protected]

Hibbitt, Karlsson & Sorensen (West), Inc.39221 Paseo Padre Parkway, Suite FFremont, CA 94538-1611phone (1) 510 794 5891fax (1) 510 794 1194e-mail [email protected]

Abacus Fatigue Calc

Documents

Transcript of Abacus Fatigue Calc