Constitutive Models for Nonlinear Finite Element Analysis of Masonry Prisms and Infill Walls

Abstract

Abstract : After much previous research, many controversial issues related to well developed design recommendations and well accepted analytical procedures for infilled frames are still unresolved. The main difficulty in evaluating the performance of bearing and shear wall structures is determining the type of interaction between the infill and the frame, which has a major impact on the structural behavior and load-resisting mechanism. A simplified model that captures the characteristics of infill masonry would be valuable, but developing one requires understanding of masonry- infilled frame behavior in much more detail than strut or beam behavior. Numerical simulations using well calibrated constitutive models are needed for parametric studies to facilitate the development and calibration of a simple, accurate infill masonry model. The objective of this study was to identify suitable numerical constitutive models and demonstrate their capabilities. Two were studied here: a cohesive interface model to simulate the behavior of mortar joints between masonry units as well as the behavior of the frame-to-panel interface; and a smeared crack finite element formulation. The interface model was able to account for the shearing, residual shear strength, and opening and closing of joints under cyclic shear loads in simple combinations of concrete blocks and mortar joints.