MultiYieldSurfaceClay
- Sensitivity_Command_Manual
The ‘MultiYieldSurfaceClay’ is an elastic-plastic material in which plasticity exhibits only in the deviatoric stress-strain response. The volumetric stress-strain response is linear-elastic and is independent of the deviatoric response. This material is implemented to simulate monotonic or cyclic response of materials whose shear behavior is pressure independent. Such materials include, for example, organic soils or clay under fast (undrained) loading conditions.
This material is available for sensitivity computation in both 2-D and 3-D models. It is another version of PressureIndependMultiYield material. However there are three differences between this model and PressureIndependMultiYield:
1. This model uses the consistent tangent modulus instead of the continuum tangent modulus.
2. This model does not support the ‘updateMaterialStage’ command.
3. This model does not support further discretization of the strain increment in each iteration.
| nDmaterial MultiYieldSurfaceClay $matTag $nd $rho $G $K $cohesion $peakShearStrain |
| $matTag | unique material object integer tag |
| $nd | number of dimensions, 2 for 2-D analysis (plane-strain), and 3 for 3-D analysis |
| $rho | saturated soil mass density |
| $G | reference low-strain shear modulus |
| $K | reference bulk modulus |
| $cohesion | peak shear (apparent cohesion at zero effective confinement) |
| $peakShearStrain | strain at peak shear, i.e., the octahedral shear strain at which the maximum shear strength is reached |
Note: For this material class, the sensitivity parameters can be: G, K, cohesion.
- Reference:
- Gu Q., Conte J.P., Elgamal A., Yang Z. (2009). “Finite element response sensitivity analysis of multi-yield-surface J2 plasticity model by direct differentiation method.” Computer Methods in Applied Mechanics and Engineering, 198(30-32):2272-2285.