Description of inelastic behaviour of structural masonry

The focus of this paper is on the description of progressive failure in structural masonry. A continuum formulation is developed here applicable to a representative volume which comprises a large number of units interspersed by mortar joints. The conditions at failure are defined by employing a critical plane approach, whereby the orientation of the localization plane is specified by solving a constrained optimization problem. The framework is subsequently extended to model the inelastic deformation process. This is accomplished by incorporating a multi-laminate approach in which the average response is derived from sliding/separation characteristics along a set of randomly distributed planes. The localized deformation is described by considering a structured medium comprising the intact masonry intercepted by a distinct macrocrack. Extensive numerical simulations are performed examining the response of brickwork in compression/tension regimes, at different orientations of the bed joints relative to the loading direction. A boundary-value problem is also studied involving an inelastic finite element analysis of a bearing masonry wall subjected to in-plane loading.