Nonlinear finite element analysis of the inelastic behavior of reinforced masonry walls

In this Dissertation an analytical method is presented for the analysis of the inelastic response of reinforced masonry wall systems to applied static loads. The method is a two level approach based on the incremental theory of elasto-plasticity. At the most basic material level the inelastic response of a basic assembly of mortar, brick, reinforcement steel and grout is investigated as an elasto plastic subassembly. This information is then used to provide an overall stress-strain model for use in the second level of the analysis, namely, an inelastic finite element analysis of the actual masonry wall system.; The brick and mortar components are modeled using a modified Proger-Drucker yield condition with compressive caps and a tension cut off to simulate cracking. The steel reinforcement is modeled as an elastic subassembly.; The method is used to investigate the response of a ductile masonry beam/column joint which was built and tested at UCSD in 1990. In the present study only monotonic loading is considered. It is shown that the numerical analysis is able to accurately track the highly nonlinear processes in this complex structural system, namely the initiation and build up of cracking, compression/shear failure and overall ductile behavior.; The method presented in this Dissertation may be used as a base for developing analytical techniques for predict in the behavior of reinforced masonry wall systems under conditions of large scale load reversal, where significant damage changes the load carrying capacity of the wall systems greatly. If such a technique can be developed, based on first principles of mechanics, then it can be used as a design tool to develop improved masonry wall designs.