Numerical model for nonlinear analysis of masonry walls

A new proposal to represent the in-plane non-linear structural behavior of masonry walls is presented. The proposal has the ability to represent unreinforced, reinforced and confined masonry, considering different configurations. The wall configurations can take into account different dimensions for the wall and sizes for bricks and joints. Additionally, the model is able to consider different bricks, mortar and interface brick-mortar material properties. The most important point in the proposal is the implementation of the joint model. The joint model is defined as a special connection considering two non-linear springs (one longitudinal and one transversal to the joint connected in parallel) and one contact element (connected in series with the springs). This configuration is able to simulate almost all the failure possibilities in the joint. The bricks are implemented considering solid finite elements, taking into account a non-linear material behaviour. The main result of the model implemented in ANSYS is the capacity curve of the wall (top displacement versus base shear). The model was used to simulate the structural behaviour of a group of walls previously tested in laboratory at the University of La Serena and the University of Chile. The results obtained with the proposed model have a good agreement with those obtained in the laboratory tests.