Modified Drucker-Prager/Cap model

The modified Drucker-Prager/Cap plasticity/creep model:

  • is intended to model cohesive geological materials that exhibit pressure-dependent yield, such as soils and rocks;

  • is based on the addition of a cap yield surface to the Drucker-Prager plasticity model (Extended Drucker-Prager models), which provides an inelastic hardening mechanism to account for plastic compaction and helps to control volume dilatancy when the material yields in shear;

  • can be used in Abaqus/Standard to simulate creep in materials exhibiting long-term inelastic deformation through a cohesion creep mechanism in the shear failure region and a consolidation creep mechanism in the cap region;

  • can be used in conjunction with either the elastic material model (Linear elastic behavior) or, in Abaqus/Standard if creep is not defined, the porous elastic material model (Elastic behavior of porous materials); and

  • provides a reasonable response to large stress reversals in the cap region; however, in the failure surface region the response is reasonable only for essentially monotonic loading.

The following topics are discussed:

Related Topics
Inelastic behavior
About the material library
Rate-dependent plasticity: creep and swelling
In Other Guides
Defining cap plasticity