Failure mechanism of masonry prism loaded in axial compression: computational aspects

In this paper, the mechanical behaviour of masonry prism under typical laboratory testing conditions, such as uniaxial compression, was simulated by means of finite element analysis by both two-dimensional and three dimensional models. The analyses were performed by assuming damage constitutive law for the component materials (mortar and bricks). The effect of lateral stresses arising from the Poisson's effect is emphasised and the main failure mechanism is identified, demonstrating the inability of usual plain-stress and plain-strain 2-D analysis to capture the actual structural response in the most common pratical cases. A modified 2-D model accounting for the out-of-plane interaction between mortar and units is therefore proposed and comparative stress-strain diagrams are presented.