Assessing seismic vulnerability of unreinforced masonry walls using elasto-plastic damage model

In this paper, the seismic vulnerability of unreinforced masonry walls is assessed by conducting a numerical study on the interaction of axial and lateral resistance. The walls are modeled in an ABAQUS environment, using a plastic damage model originally developed by Lubliner et al. (Int J Solids Struct 25(3):299-326, 1989) and further extended by Lee and Fenves (J Eng Mech ASCE 124(8):892-900, 1998). The model yields interesting interactive collapsemechanisms that occur as the axial loading on the wall is increased. The different modes of failure identified as the axial load is increased include (i) rocking mode, (ii) sliding mode, (iii) staggered head/bed joint failure, (iv) diagonal cracks through wall blocks accompanied by staggered head/bed joint cracking, and (v) crushing of wall blocks or bricks.