A plane stress softening plasticity model for orthotropic materials

A plane stress model has been developed for quasi-brittle orthotropic materials. The theory of plasticity, which is adopted to describe the inelastic behaviour, utilizes modern algorithmic concepts, including an implicit Euler backward return mapping scheme, a local NewtonÐRaphson method and a consistent tangential sti¤ness matrix. The model is capable of predicting independent responses along the material axes. It features a tensile fracture energy and a compressive fracture energy, which are di¤erent for each material axis. A comparison between calculated and experimental results in masonry shear walls shows that a successful implementation has been achieved.