Determination of masonry crack evolution due to differential displacements: a numerical study*

Abstract

ABSTRACTBrick walls of ceramics without any mortar covering or paint are used extensively in building façades in Spain. One of the most used masonry wall systems is based on non‐bearing panels partially supported, about two‐thirds of the brick width, over the edge beams of the structural skeleton. The edge beam is veneered with special thinner bricks to achieve the visual continuity of the façade. A considerable number of these walls show cracking. In a previous work, finite element simulations were performed in order to gain insight into the causes of cracking. A special finite element, based on the strong discontinuity analysis and the cohesive crack theory, is used in the numerical simulations. The results agree with the overall cracking patterns observed but if an imposed displacement is applied in the range allowed by the standards, extensive cracking occurs. This implies that the design displacements are not the actual ones. In this work, an elastic study using the principle of superposition is used to determine the effective deflections under service loading. Then, these deflections are applied to the structure and the evolution of cracking is studied. This study shows that the masonry panels of the first and last store have the major probability of cracking. Another parametric study is carried out changing the elastic and tensile properties of the masonry. This study shows that although the cracking of the masonry panels starts at different loads for different tensile properties, the crack patterns are similar for a given panel geometry and loading. This numerical study provides a method of design to determine the crack width for different geometries, loadings and fracture properties.