Optimum Placement Of Dampers And Fracture Analysis Of Frame Structures Based On Vector Form Intrinsic Finite Element

The traditional anti-seismic structure system achieves the role of the anti-earthquake by enhancing the performance of the structure itself, but energy dissipation structure system dissipates the earthquake energy by attaching the energy dissipation devices to it. The passive control strategy with viscous damper are more and more applied in engineering structures because of its simple structure, no need for external source of energy and remarkable effect of seismic reduction.The Vector Form Intrinsic Finite Element (VFIFE) is a new method for analysis of structural behavior. Space points are used to describe structural behavior and their motion are controlled by Newton’s second law. VFIFE is very suitable for analyzing Structural nonlinearities and discontinuities. In this paper, the Vector Form Intrinsic Finite Element was introduced into the analysis of structures with viscous damper. The main research work lists as follows:(1) the basic concept and principle of VFIFE is stated in detailed. The effect of damper is simulated by adding external force to the space point then an analysis method based on VFIFE is put forward for structural dynamic problems with viscous damper. (2)the MATLAB program based on the analysis method is used to analyze a single-particle model and a five-floor frame structure and the result compared with SAP2000’verify the validity of the methods and procedures. (3)a model of 3-bay, 7-story frame structure is established based on VFIFE, considering side-span evenly layout, weight coefficient layout and circular layout these three optimization placement of damper, choose EL Centro wave and Taft wave to conduct time-history analysis. Structural response’control effect of three kinds of damper layout is compared. (4)circular layout optimization program combined with VFIFE can find the row vector and the column vector of the layout of the damper at one go, the program is verified by placing one by one. (5)The fracture criterion and modeling algorithm of beam element are proposed. The fracture behavior of the frame under earthquake and impact load before and after the layout of damper is studied by VFIFE program. The role of damper in the collapse of frame structure is analyzed.The analysis method based on VFIFE put forward in this paper can be well used for optimization placement of damper in frame structure, dynamic analysis and failure analysis of structures with viscous damper under various loads. The suggested method also provides a new idea for complicated structural behavior analysis.