Inelastic anisotropic constitutive models based on evolutionary linear transformations on stress tensors with application to masonry

Abstract

The formulation of constitutive models for anisotropic materials such as masonry is a problem of large complexity. One possible way is to define linear transformations on the stress tensors using fourth-order transformation tensors that carry all the anisotropic information of the material. In the present paper, a new type of evolutionary linear transformation tensor is defined, which can change the values of its components along with the evolution of internal variables. This means the transformation laws are defined according to the current plastic and damage levels, and allows the constitutive model to describe totally different hardening and softening behaviours of the material along different directions. First, a general procedure of formulation of anisotropic constitutive models is given. Second, as a specific example, an orthotropic plastic–damage constitutive model for masonry is presented. Finally, the proposed constitutive model is validated by comparing finite element results with experimental ones pertaining to simple masonry structures under static and cyclic loading.