Experimental Investigation of the Damage Mechanics of Masonry under Dynamic In-plane Loads

The evolution of the damage mechanic properties for un-reinforced masonry panels under dynamic loads is critical in a time-domain analysis of masonry shear walls. This research project experimentally investigates the evolution of the properties of the damage variable for unreinforced masonry panels, subject to dynamic in-plane displacement controlled strain. This paper presents the theoretical basis for the estimation of the Damage Variable for masonry shear walls, and outlines briefly the test program and methodology. We discuss the observed changes in the effective stiffness properties of the masonry panels from the first tests on a series of masonry panels. Then comment on the changes in the test protocol resulting from these early experiments. The loading pattern used in the experimental work is designed to be consistent with the seismic range of frequencies and amplitudes. A shear test rig, developed for this project at the University of Newcastle, tests square masonry panels. The rig provides non-proportional uniform compression in two normal planes and a time varying shear load using an uni-axial ram to provide in-plane loading.