Nonlinear Finite Element Seismic Analysis Of Reinforced Concrete Frame Structure With Opening Infill Wall

Recent years, during the process of damage appraisal consultation and statistics of the earthquake damage buildings after earthquakes happened in China, the buildings of reinforced concrete frame structure with infill walls were extremely damaged. Then it is concerned gradually that the infill walls can changed the mechanic behavior. In project the finite element method is used to analyze the reinforced concrete frame structure with the bar or beam elements, and the infill walls were taken as uniformly distributed load applied to the beams, which was not considered the stiffness influence of the infill wall directly to the structure. the stiffness influence was only considered by the reduction of the natural period of vibration.In this study, a groups of space frame models with three-bay three-two cross are designed with usual method according current national specifications by SAP2000. According to the middle frame supported frame, the same solid model was to be built with ANSYS, which was forced by horizontal load in order to simulate the earthquake. Then a quasi-static analysis was done.Firstly, systematic research was made with the whole framework models of7degrees seismic intensity and the variations of the first vibration period were found. Secondly, the crack development of models and the internal forces of the framework of beams and columns were contrasted to analyze the affect in mechanical behavior of the frame structural members, which is due to the infill walls. Finally, three more groups of flat frame models in the6,7,8seismic intensity with SAP2000were designed. After collected all the results of layer displacement of all the models of SAP2000and ANSYS. the differences between two of them were studied and useful measures of how to improve the structural design software on behalf of SAP2000, which made the elasticity compute of the infill walls as simply as possible may be found.After the contradistinction and analysis of all the data above, series of proposals about the seismic design could be made, which were consist of the proposals about the arranges of the infill walls in the frame structure, a better beam-column’s design of the frame structure, the revises of the natural period of vibration reduction factor, the value of the layer displacement adjustment factor in seismic design and the revises of the limit of the story drift, etc.