Porous Plasticity
Use the Porous Plasticity subnode to define the properties of a plasticity model for a porous material.
Porous Plasticity Model
Use this section to define the plastic properties of the porous material.
Yield Function F
The Yield function F defines the limit of the elastic regime F(σ, σys) ≤ 0.
Select a Yield function F for the porous plasticity criterion — Shima-Oyane, Gurson, Gurson-Tvergaard-Needleman, Fleck-Kuhn-McMeeking, or FKM-GTN.
Shima-Oyane
For Shima-Oyane enter the following data:
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Initial yield stress σys0.
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Shima-Oyane parameter α.
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Shima-Oyane parameter γ.
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Shima-Oyane parameter m.
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Initial void volume fraction f0.
Gurson
For Gurson enter the following data:
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Initial yield stress σys0.
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Initial void volume fraction f0.
Gurson-Tvergaard-Needleman
For Gurson-Tvergaard-Needleman enter the following data:
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Initial yield stress σys0.
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Tvergaard correction coefficient q1.
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Tvergaard correction coefficient q2.
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Initial void volume fraction f0.
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Critical void volume fraction fc.
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Failure void volume fraction ff.
Fleck-Kuhn-McMeeking
For Fleck-Kuhn-McMeeking enter the following data:
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Initial yield stress σys0.
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Initial void volume fraction f0.
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Maximum void volume fraction fmax.
FKM-GTN
For FKM-GTN enter the following data:
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Initial yield stress σys0.
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Tvergaard correction coefficient q1.
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Tvergaard correction coefficient q2.
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Initial void volume fraction f0.
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Maximum void volume fraction fmax.
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Void volume fraction cut-off for GTN model fGTN.
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Void volume fraction cut-off for FKM model fFKM.
Each of the material properties can either be defined obtained From material, or as User defined. In the latter case, enter a value or an expression.
See also Porous Plasticity in the Structural Mechanics Theory chapter.
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To compute the energy dissipation caused by porous compaction, enable the Calculate dissipated energy check box in the Energy Dissipation section of the parent material node (Linear Elastic Material or Nonlinear Elastic Material).
Location in User Interface
Context Menus
 Solid Mechanics>Linear Elastic Material>Porous Plasticity
 Solid Mechanics>Nonlinear Elastic Material>Porous Plasticity
 Membrane>Linear Elastic Material>Porous Plasticity
 Membrane>Nonlinear Elastic Material>Porous Plasticity
Ribbon
Physics tab with Linear Elastic Material or Nonlinear Elastic Material node selected in the model tree:
Attributes>Porous Plasticity