Published 6 issues per year
ISSN Print: 1543-1649
ISSN Online: 1940-4352
Indexed in
GENERAL FORMULATION OF A POROMECHANICAL COHESIVE SURFACE ELEMENT WITH ELASTOPLASTICITY FOR MODELING INTERFACES IN FLUID-SATURATED GEOMATERIALS
ABSTRACT
The paper formulates and implements a fluid-saturated poromechanical cohesive surface element (CSE) based upon biphasic (solid-fluid) mixture theory at small strain, with strong discontinuity kinematics. The goal is to be able to introduce strong discontinuity kinematics directly into the coupled variational form in order to derive the balance of linear momentum and mass within the discontinuity domain. This method is compared to approaches that derive the additional terms directly from underlying physical considerations. This approach is useful when extending the method to finite strain, partially saturated, and heated conditions. The Strong form (coupled partial differential equations) is presented, upon which Weak and Galerkin forms are formulated using different representations of the fields outside and inside the discontinuity domain. A mixed Q6P4 six-noded CSE is implemented within the coupled nonlinear Finite Element (FE) equations, along with a mixed Q9P4 biquadratic/bilinear quadrilateral for the surrounding bulk porous continuum. Numerical examples demonstrate the features of the CSE for fluid-saturated geomaterials.