Constitutive model for the nonlinear cyclic behavior of brick masonry structures

Abstract

The present work focuses on the development of a continuum constitutive model that describes the structural behavior of brick masonry. The model, following a phenomenological approach, is based on a Total Strain Rotating Crack concept and it incorporates the orthotropic behavior of the material. This is achieved by varying the elastic and inelastic parameters (Young’s modulus, tensile and compressive strengths and fracture energies) with respect to the angle θ between the principal stresses and the mortar joints. In this way, a different mechanical behavior of the principal stresses is obtained based on the directionality of the mortar joints and the expected failure mechanism along them, i.e. low dissipative behavior for bed-joint’s opening and high dissipative behavior for diagonal shear sliding. The material model is implemented in a non-linear finite element program and is validated against quasi-static, cyclic, in-plane tests performed on masonry walls at TU Delft.