|
|
| (2 intermediate revisions by the same user not shown) |
| Line 1: |
Line 1: |
| {{CommandManualMenu}}
| |
|
| |
|
| This command is used to construct a multi-dimensional material object that that
| |
| follows the constitutive behavior of a cyclic elastoplasticity model for large post-
| |
| liquefaction deformation.
| |
|
| |
| {|
| |
| | style="background:yellow; color:black; width:800px" | '''nDmaterial CycLiqCP $matTag $G0 $kappa $h $Mfc $dre1 $Mdc $dre2 $rdr $alpha $dir $ein <$rho>'''
| |
| |}
| |
|
| |
| CycLiqCP material is a cyclic elastoplasticity model for large post-liquefaction
| |
| deformation, and is implemented using a cutting plane algorithm. The model is
| |
| capable of reproducing small to large deformation in the pre- to post-liquefaction
| |
| regime. The elastic moduli of the model are pressure dependent. The plasticity in the
| |
| model is developed within the framework of bounding surface plasticity, with special
| |
| consideration to the formulation of reversible and irreversible dilatancy.
| |
| This model does not take the state of sand into consideration, which could limit
| |
| its simulation performance during large variations of void ratio or confining pressure.
| |
|
| |
| The model has been validated against VELACS centrifuge model tests and has used
| |
| on numerous simulations of liquefaction related problems.
| |
|
| |
| When this material is employed in regular solid elements (e.g., FourNodeQuad,
| |
| Brick), it simulates drained soil response. When solid-fluid coupled elements (u-p
| |
| elements and SSP u-p elements) are used, the model is able to simulate undrained and
| |
| partially drained behavior of soil.
| |
|
| |
| During the application of gravity load (and static loads if any), the user is suggested to
| |
| set the material behavior to be linear elastic, with the updateMaterialStage command:
| |
|
| |
| updateMaterialStage -material $matTag -stage 0
| |
|
| |
| After the gravity load stage, the material stage should be updated to achieve the
| |
| desired elastic-plastic stress-strain response.
| |
|
| |
| updateMaterialStage -material $matTag -stage 1
| |
|
| |
|
| |
| ----
| |
|
| |
| {|
| |
| | style="width:150px" | '''$matTag ''' || integer tag identifying material
| |
| |-
| |
| | '''$G0 ''' || A constant related to elastic shear modulus
| |
| |-
| |
| | '''$kappa ''' || A constant related to elastic bulk modulus
| |
| |-
| |
| | '''$h ''' || Model parameter for plastic modulus
| |
| |-
| |
| | '''$Mfc''' || Stress ratio at failure in triaxial compression
| |
| |-
| |
| | '''$dre1''' || Coefficient for reversible dilatancy generation
| |
| |-
| |
| | '''$Mdc''' || Stress ratio at which the reversible dilatancy sign changes
| |
| |-
| |
| | '''$dre2''' || Coefficient for reversible dilatancy release
| |
| |-
| |
| | '''$rdr''' || Reference shear strain length
| |
| |-
| |
| | '''$alpha''' || Parameter controlling the decrease rate of irreversible dilatancy
| |
| |-
| |
| | '''$dir''' || Coefficient for irreversible dilatancy potential
| |
| |-
| |
| | '''$ein''' || Initial void ratio
| |
| |-
| |
| | '''$rho''' || Saturated mass density
| |
| |}
| |
|
| |
| The material formulations for the CycLiqCP object are "ThreeDimensional" and "PlaneStrain".
| |
|
| |
|
| |
| ----
| |
|
| |
|
| |
| REFERENCES:
| |
| Zhang J.M. and Wang G., 2012, “Large post-liquefaction deformation of sand, part I: physical mechanism, constitutive description and numerical algorithm”, Acta Geotechnica.
| |
|
| |
|
| |
| ----
| |
|
| |
| Code Developed by: <span style="color:blue"> Rui Wang, Tsinghua University</span>
| |