Rigid Element Model for non-linear Analysis of Masonry Facades Subjected to out-of-Plane Loading

A simplified method for investigating the out-of-plane behaviour of masonry walls subjected to seismic loading is presented. Survey of the large walls of monuments hit by earthquakes reveals that in many cases the damage is mainly due to lateral actions, and the crack patterns often tend to subdivide the walls into a number of rigid blocks. In the present study such walls are modelled as a series of plane rigid elements in which only the out-of-plane displacements are considered. The elements are quadrilateral and are connected to each other in the middle of their adjoining sides by hinges that can be regarded as spherical joints at which all the deformation takes place. The mechanical characteristics of these connections are defined so as to approximate the brittle behaviour of masonry material. The results obtained using a limited number of elements are in accord with the observed out-of-plane response of masonry panels.