Modeling of out-of-plane behavior of masonry walls

The flexural behavior of rectangular masonry sections is investigated by considering nonlinear stress-strain in compression and limited-tension material. A preliminary analysis shows that, with variation in the parameters specializing with the adopted conventional constitutive law, the experimentally observed behavior of different kinds of masonry materials can be approximated. Subsequently, moment-curvature dimensionless curves are derived numerically by satisfying the equilibrium equations of the section. In the case of negligible tensile strength these curves exhibit a typical shape that can be approximated by analytical expressions; consequently, suitable functions are proposed that are governed by only a few parameters which depend on the compression level of the section and the available ductility of the material. The reliability of the proposed modeling procedure is also verified by using the experimental results of a previous study, where masonry elements subjected to an increasing eccentric normal load were considered. Therefore, the analytically defined flexural behavior is transferred to the characteristic sections of a discrete model of slender masonry column, in order to reproduce the experimental results of full-scale tests on bearing masonry walls subjected to increasing lateral deflections for stability analyses. Comments on the results obtained with this model would be useful for further investigations. © 2009 ASCE.