Nonlinear Dynamic Behavior of Unreinforced Masonry Walls Subjected to Out-of-Plane Loads

Abstract

An analytical model for the nonlinear dynamic behavior of unreinforced masonry walls subjected to out-of-plane loading is developed. The formulation is based on variational principles, dynamic equilibrium conditions, and the nonlinear constitutive behavior of the materials involved. The model focuses on one-way action through the height of the wall, which is modeled as a structural assembly of masonry units connected by mortar joints. The masonry units and the mortar joints are modeled as first-order shear deformable flexural members with large displacements, moderate rotations, and small strains. The cracking and the nonlinear behavior of the mortar material, the opening and closing of cracks, the rocking phenomenon, and the development of a time-dependent arching force are also considered. A numerical study that examines the capabilities of the proposed model and quantifies some aspects of the dynamic behavior of the masonry wall is presented. It is shown that the dynamic behavior of the wall is a nonpe...