Simple homogenization model for the non-linear analysis of in-plane loaded masonry walls

A simple homogenized model for the non-linear and limit analysis of masonry walls in-plane loaded is presented. A rectangular running bond elementary cell (RVE) is discretized by means of a few plane-stress three-noded triangular elements and interfaces. Non-linearity is concentrated on brick-brick interfaces and joints reduced to interface, exhibiting a frictional behavior with limited tensile and compressive strength with softening. Homogenized masonry behavior is then implemented at a structural level in a novel FE non-linear code relying on an assemblage of rigid infinitely resistant triangular elements and non-linear interfaces, exhibiting deterioration of the mechanical properties. Non-linear analyses are conducted on full scale walls - a deep beam and a windowed shear wall, for which experimental and numerical data are available in the literature - with a very limited computational effort. To circumvent some typical drawbacks of standard FE approaches, at each load step, all interfaces are assumed to behave as an elastic-perfectly plastic material and the discretized non-linear problem is solved by means of a standard sequential quadratic programming algorithm. (C) 2011 Elsevier Ltd. All rights reserved.