A plane-stress plasticity model for masonry for the explicit finite element time integration scheme

Masonry is a composite material and can be considered anisotropic on a macroscopic scale, i.e., masonry exhibits different properties in different directions, both in the elastic and inelastic range. Like other quasi-brittle materials, masonry exhibits softening and hardening behavior after failure for compression and tension. In this paper a smeared continuum plasticity model of masonry is presented as well as it numerical implementation in an explicit finite element time integration scheme, as such a material model does not exist for a commercial explicit finite element solver. The implementation is done by writing a user-defined material model (VUMAT) as a Fortran subroutine in the commercial software ABAQUS Explicit. The material model is tested both in uniaxial and biaxial loading against similar tests from earlier research. The results show good agreement with earlier research.