Seismic vulnerability of masonry walls through an innovative voxel limit analysis homogenization approach

This paper addresses the seismic vulnerability of masonry walls, which is assessed using a homogenization-based limit analysis approach for modelling their out-of-plane behavior. The finite element mesh for the numerical model of the masonry wall or panel under investigation is generated from the actual geometry through a voxel approach: once the in-plane and transversal layout of the wall are identified, one voxel (i.e. 3D pixel) is transformed into a finite element. One stretcher bond masonry test-window is considered in this paper. Its out-of-plane behavior is then assessed by solving a limit analysis problem scripted into a Matlab code, whose formulation is also based on homogenization, evaluating their collapse load multiplier. The post-processing stage consists in the derivation of homogenized out-of-plane failure surfaces for the considered test-window. These are expressed in terms of bending moments, which represent the bending strengths of the test-window; they are then compared to similar homogenized failure surfaces obtained in a previous work for validation. Eventually, the collapse mechanisms for the considered test-window are identified and critically discussed.