Nonlinear Analysis Of Masonry Applying The RVE Homogenization Methods

Masonry structure is one of the most commonly used structures. In addition to its low cost, abundant raw materials and convenient maintenance, with the arising of new types of mortar and blocks and the development of construction methods, masonry by now is used more widely in civil engineering. However, the research in masonry theory is dropped behind by masonry's engineering practice. Today, The mainly used masonry analysis method is to establish mechanics models directly, which based on the grasp of masonry's holistic characters abstracted form experiments. Therefore numerous experiment data are required. The newly arisen homogenization theories of masonry, derived from composite material mechanics, bases on the characteristics of masonry's constituent phases and the analysis of their blend effect, so that the mechanics characters of the masonry representative volume element (RVE) can be obtained. Then the RVE is applied in complete structures to describe the structures mechanics characters. The primary task of masonry homogenization is to pose an integrated theory path of equivalent processes that give the integral behaviors of masonry form local behaviors of blocks and mortar, and of characterizing complete structures. With the help of the theory, the masonry experiments can be greatly simplified.However, the short period of development leads many of the masonry homogenization theories based on the elastic assumption. This thesis is an explore to the immature theories through elasto-plastic finite element analysis (FEA). To demonstrate the feasibility of FEA used in masonry homogenization, the following tests are conducted: 1. The behavior simulation of masonry RVE subjected to uniaxial forces; 2. The calculation of equivalent elastic modules and Poisson's ratio of masonry RVE; 3. The behavior simulation of masonry RVE subjected to combined pressure and sheer force; 4. The influence of RVE's size on its mechanic behaviors; 5. The decrease test of influences caused by complex forces applying methods and constraining forms on masonry RVE during FEA process. Compared with actual masonry, the analysis results suggest FE method can be use in the process of masonry homogenization. Moreover, the definition of masonry RVE is similar to finite element in some extent. Accordingly, it is consideredwhether the FE method can be used again in the description of masonry RVE to complete structures. Therefore, the equivalent parameters of masonry RVE are used in finite elements to simulate a three-storey experiment specimen created by Prof. Wankang Luo, et al.[1], of Chongqing University. The fact that the simulation results are appropriate to the experiment in principle implies it is reasonable that as a substitute for the masonry's constituents, RVE can be used in the description of complete structures, and implies the FE method conforms to the masonry homogenization theories in some aspects and the masonry homogenization theory is a new mechanic way to analyze large masonry structures.