Numerical Simulation And Analysis On Infill Cracks Of Frame Based On Discrete Element Method

The purpose of the approach of cracks in infill wall of frame is to solve the issue of cracks in infill wall of frame. It was good for architectural activity, for improving quality of buildings, and for reducing the contradictions between building owner and company of real estate; what is more, it was also good for the reform of wall and the generalization of new style building materials. So, the research of cracks in infill wall is of great theory and actual meaning.First we discuss the investigation and study of infill wall in frame. According to the case of investigation, the rules of the cracks develop are as below: 1 conjoining of infill wall and frame is most easily to find cracks. 2 cracks is easily to be found around the four corners of jamb and where the conduits go. 3 cracks in infill wall of top frame are more than other stories 4 there are vertical cracks besides boundary cracks in long infill wall. 5 the cracks of sintered wall are less than that of un-sintered wall.In this paper, the discrete element method is used to the numerical simulation. After reviewing and summarizing the state of history and present for discrete element method, a model which is based on Cundall existing model is presented. The basic concepts, failure criteria, formula and determination of analytical parameters such as coefficient of damping and time step of the model are presented. And the test research projects are undertaken to value the parameters of the model, such as spring modulus.A software is programmed based the extended models.which can analyze the development of cracks in infill wall of frame. For the maintainability and readability the codes are programmed in C++ which has object—oriented property. The computational efficiency is improved by applying different lists to different contact type technique in the program.Finally, some conclusions are drawn according to the results of numerical simulation: 1. the cracks mainly happen in the mortar of the wall. Conjoining of infill wall and frame and the middle part of the wall is most easily to find cracks. 2 different sizes of the walls have different rules of the cracks develop, the cracks grow as the length of wall grows. 3 the thickness of the mortar have effects on the development of cracks. When the thickness of the mortar is too big, then the strength of the masonry blocks is weakened and cracks are developed more easily. 4.taking constitutions can control the cracks effectively.