Masonry subjected to semi-cyclic compression: Inelastic response modelling

Abstract

A series of load tests on unreinforced masonry elements (triplets and wallettes with inclined bed joints) subjected to semi-cyclic compression have been performed in order to investigate the response of masonry under such loading conditions. The specimens exhibited inelastic and extremely nonlinear response and substantially different behaviour during the loading, unloading and reloading phases. Further investigations revealed that the observed behaviour was governed by the response of the block-mortar interfaces. A new mechanical model has been developed, which combines the conventional stress–strain model for the masonry with a non-linear model describing the response of the block-mortar interfaces. The model was calibrated using the Monte-Carlo simulation method and validated against the semi-cyclic compression tests on masonry specimens. The model developed is expected to improve significantly the simulation of the force–displacement response of unreinforced masonry walls subjected to seismic loading.