A simplified micro-model based on discrete elements and elastic bodies for non-linear static analysis of in-plane loaded masonry panels

In this paper, a simplified micro-model based on a combination of continuum (2D) and discrete elements was developed to estimate non-linear behavior and failure prediction of masonry panels subjected to in-plane loads. Bricks were substituted by 2D elastic elements which connected via eight bi-component non-linear springs to each other. Each spring has axial and shear behavior which is represented by mortar axial stress–strain curve, including softening and brick–mortar cohesion-friction law, respectively. Substantial simplifications are accomplished due to employing elastic panels and concentration non-linearity at the discrete elements in terms of the possibility of implementation in commercial software. The validation process was conducted at two levels; first: a masonry cell under possible in-plane loading conditions and second: ten experimental panels having different geometrical and mechanical properties subjected to vertical and horizontal actions simultaneously. The obtained results including global behavior and crack pattern were compared with experimental ones as well as available numerical predictions from the literature. High accuracy was observed despite convergence ease and reduction in both pre-processing and analysis time.