Seismic Performance Analysis Of Isolated Frame Structures

Base isolation is at the top of the base and set the isolation layer between the upper structure, blocking up department structure seismic action. Using the base isolation system to extend the cycle structure, to avoid the site predominant period,can make the seismic energy is mainly composed of isolation layer, at the same time to dissipation of earthquake energy and the appropriate damping limit displacement of isolation layer response to allow range.By means of finite element software ANSYS, this paper established a number of different layers of reinforced concrete frame structure and the corresponding structure.No ready-made isolation bearing in ANSYS, therefore, this article adopts Combin14element(simulated lead core rubber isolation bearing the vertical stiffness) and Combin40 unit(simulated) the level of lead core rubber isolation bearing stiffness was simulated by combination of isolation bearing. Frame column and beam simulation adopt Beam188 unit,floor with Shell63 element.Through the dynamic time history analysis of two kinds of structure, the following conclusions: isolation of the structure of the interlayer shear, interlayer displacement, maximum acceleration are far less than the seismic structure; Different column spacing and height to width ratio and floor open hole rate also have certain influence to structure: the column from the greater, the smaller the stiffness of the structure, cycle thus increasing, has good isolation performance; The structure of the open hole rate, the greater the isolation performance is poor; The aspect ratio of the buildings within the scope of the permit, the bigger the against earthquake.In this article, through analysis of isolation frame structure and research,confirmed the characteristics and the advantages of the base isolation structure,provide the basis for engineering application.