Nonlinear Analysis And Seismic Performance Research For Multilayer Masonry Structure

According to earthquake damage statistics, multilayer masonry structures were damage easily than other structures. So it is important to do some research about how to economically and effectively improve seismic capacity of masonry structure, especially do some damage analysis to the buildings which did not consider seismic or did not meet the existing seismic norms and standards, and determine the seismic capacity of unreinforced and reinforced structure. Because of the obvious diphase of masonry which is made up by brick and mortar, during nonlinear analysis and seismic performance research of masonry structure, there are so many things leading to some error between the analysis results and the actual situation exists, such as modeling with different elements, different constitutive relationship, different yield norm and different convergent norm.A FE model for masonry element was established based on the discrete element approach and the continuous element approach, and the element model and the constitutive relationship for masonry applicable to dynamic analysis of masonry structures was determined by comparison of FE analysis results by ANSYS and test results, a masonry structural model built in the sixties of last century was established by using Representative Volume Element, damage process of the masonry structure under earthquake through transient seismic analysis was discussed, and the change of seismic capacity was obtained by comparing the results of multilayer masonry structure and the same sprayed concrete reinforced structure through transient seismic analysis.Through researching, it is shown that the structural model for masonry presented in this paper by using Representative Volume Element could effectively simulate the structural behavior of masonry structures under seismic action and the development of crushing and cracking, seismic capacity was greatly increased after the structure reinforced, because sprayed concrete shared a lot of principal tensile stress that let masonry wall avoid shear failure, and the walls and floors were restrained by sprayed concrete walls and constructional columns when the structure had dehisced, which increased the tensibility and the capacity of collapsed resistance, transferred stress concentration of the walls, reduced the seismic stress of masonry walls.