Material Modeling

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gTutorial on using an Abaqus/CAE Plug-in to parse test data

Abaqus 6.11

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Tod DalrympleSIMULIA Great Lakes Region

Outline

• Motivation• Approach

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pp• Usage / Validation• Summary

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Motivation: Test Data

Loading

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Unloading / reloading(Mullins' effect)

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Permanent set

Goal: Ability to model the nonlinear loading, permanent set and,

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optionally, unloading / reloading (Mullins’ effects)

Approach

e pF F F

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e p= ⋅F F FLee (1969)

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Multiplicative split of the deformation gradient (motivated by crystal plasticity)

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y p y)Plasticity is modeled with isotropic hardening Mises plasticityHyperelasticity can be modeled with any isotropic hyperelastic models available in Abaqusmodels available in AbaqusCan be combined with Mullins’ effect to capture damaged response during unloading after initial loading

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Usage, CAE GUI Plug-in – for Test Data Parsing

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Usage, CAE GUI Plug-in – for Test Data ParsingCharacterize from experimental data using CAE plug inCharacterize from experimental data using CAE plug-in

The plug-in automatically extracts loading, unloading and permanent set data from uniaxial and biaxial test data

Edi h d ( ki k dd j )

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Edit the data (remove any kinks, sudden jumps)

Create a CAE material

Experimental dataExperimental data

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CAE GUI

Test Data

CAE GUI

Test Data

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Loading, unloading Loading, unloading

ParsingParsing

CAE Material (*HyperCAE Material (*Hyper

and permanent setand permanent set

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CAE Material ( Hyper elastic, *Plastic, *Mullins)CAE Material ( Hyper elastic, *Plastic, *Mullins)

Usage, CAE GUI Plug-in – for Test Data Parsing

• Process two modes of test data, namely, uniaxial and biaxial.• For each mode, the GUI will help users identify loading, permanent

t d ti ll l di / l di d t i th i t t d t

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set and optionally, unloading / reloading data in their test data.• Create data for the keywords: *Hyperelastic, Test Data, *Plastic and optionally, *Mullins Test Data

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• The plug-in can be downloaded from SOSS Answer #3522http://abaqus.custhelp.com/cgi-

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bin/abaqus.cfg/php/enduser/std_adp.php?p_faqid=3522&p_created=1193254530

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Validation

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Abaqus response from unit cube analysis, file st_epdm.inp

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q p y _ p p

Summary

• Multiplicative split of deformation gradient• Following keywords can be combined

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• *MULLINS EFFECT (optional)• *PLASTIC TYPE=ISOTROPIC

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• Can be used to model filled elastomers and thermoplastics that show• Permanent strain upon removal of load and/or

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• Damaged unloading behavior

• Process test data through a CAE GUI plug-in• Current LimitationsCurrent Limitations

• Can not be combined with hyperelastic rate effects such as hysteresis or viscoelasticity

Will work with rate independent isotropic hardening plasticity

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• Will work with rate-independent isotropic hardening plasticity

Thank You

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