Cap and Cutoff
Use the Cap and Cutoff subnode to define additional contributions to the plasticity model defined in the parent Pressure-Dependent Plasticity, Soil Plasticity or Elastoplastic Soil Material node.
You can add a Cap and Cutoff node to the Elastoplastic Soil Material node when the Hardening Soil or the Hardening Soil Small Strain model is selected. In this case, the variable for the Initial pressure limit pc0 is called Preconsolidation pressure.
Compression Cap
Select the Cap model — Elliptic, Planar, Cam-clay, or None.
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For Elliptic, enter the Initial pressure limit pc0 and the Initial ellipse centroid pcc0. The ellipse aspect ratio is then derived from the intersection of the ellipse with the criterion defined in the parent node.
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For Planar, enter the Initial pressure limit pc0.
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For Cam-clay, enter the Initial pressure limit pc0.
Select the Hardening model — Perfectly plastic (no hardening), Linear, Exponential, or Hardening function.
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When Linear is selected from the list, the default Hardening modulus Kc is taken From material.
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When Exponential is selected from the list, the default Hardening modulus Kc and the Maximum volumetric plastic strain εpvol,max are taken From material.
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When Hardening function is selected from the list, the default Hardening modulus pch and the Maximum volumetric plastic strain εpvol,max are taken From material.
Select the Hardening variable — Volumetric plastic strain, Equivalent plastic strain, or User defined.
See also Compression Cap in the Structural Mechanics Theory chapter.
Tension Cutoff
Select the Cutoff model — Mean stress, Rankine, or None.
When Mean stress is selected from the list, enter a value or an expression for the Mean stress limit σm,t. Use this value or expression to constrain the failure criterion model with a maximum allowed pressure in tension.
When Rankine is selected from the list, enter a value or an expression for the Tensile strength σts. Use the tensile strength to constrain the failure criterion with a maximum principal tensile stress.
See also Tension Cutoff in the Structural Mechanics Theory chapter.
Advanced
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog.
Select the Smoothing method to intersect the cap or cutoff criterion with the plasticity criterion — Automatic, Manual tuning, or User defined.
When Manual tuning is selected, it is possible to specify the relative transition zone where the cap or cutoff criterion intersects with the criterion specified the parent node. Enter the Cap smoothing multiplier fcap and the Cutoff smoothing multiplier fcutoff. Each multiplier scales the size of the transition zone for the Automatic option.
When User defined is selected, it is possible to specify the transition zone where the cap or cutoff criteria intersects with the failure criterion specified the parent node. Enter the Cap smoothing parameter σc,off and the Cutoff smoothing parameter σt,off.
When the Hardening model for the cap is other than Perfectly plastic, select the Allow cap softening checkbox to soften the cap when loaded in tension.
Location in User Interface
Context Menus
Solid Mechanics > Linear Elastic Material > Pressure-Dependent Plasticity > Cap and Cutoff
Solid Mechanics > Nonlinear Elastic Material > Pressure-Dependent Plasticity > Cap and Cutoff
Solid Mechanics > Hyperelastic Material > Pressure-Dependent Plasticity > Cap and Cutoff
Solid Mechanics > Linear Elastic Material > Soil Plasticity > Cap and Cutoff
Solid Mechanics > Nonlinear Elastic Material > Soil Plasticity > Cap and Cutoff
Solid Mechanics > Hyperelastic Material > Soil Plasticity > Cap and Cutoff
Solid Mechanics > Elastoplastic Soil Material > Cap and Cutoff
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Physics tab with Pressure-Dependent Plasticity, Soil Plasticity, or Elastoplastic Soil Material node selected in the model tree:
Attributes > Cap and Cutoff