Experimental And Numerical Studies On Mid-column Pounding Between Two Adjacent Steel Frame Structures

The different dynamic characteristics of the adjacent structures make them pounding occur if the at-rest separation is not sufficient to accommodate their relative motions. Poundings may cause both structural and architectural damages, in some cases, it may lead to collapse of the whole building. In our country, a large number of existing buildings along the street, which with small space even no, has the very high risk of collision. Therefore, research on the problem of pounding analysis and mechanism study has important meaning.Seismic pounding is roughly divided into four categories: floor-floor pounding、mid-column pounding、eccentric pounding and terminal building pounding. Among them the mid-column pounding often leads to the vertical stress component damage and causes the structure collapsed. For mid-column pounding problem, this dissertation completed a shaking table test of the adjacent multi-storey steel frames, which the eccentric mass of frame is taken into account, the study aims at mid-column pounding of adjacent multi-storey structures impact on the dynamic responses of the structure by experiment, and confirmed the FEM model through predicting the test results, in addition, The effects of the pounding dynamic responses are also discussed by parameter analysis. The main contents are listed as follows:(1) Design experiment models based on resembled theory and finish a shaking table test of the adjacent two-storey and three-storey frames, record the pounding force, displacement of floor、acceleration and strain of the dangerous section under different PGA level of ground motion and simple harmonic excitation, to research the seismic mid-column pounding impact on dynamic response of structures.(2) A refined FEM is established by Abaqus/CAE to numerical reproduce the experiment and verify the rationality of the numerical model by contrasting test results and the numerical simulation results.(3) Change the parameters of seismic pounding in FEM, including the PGA level of imported ground motion、distance of adjacent structure and mass eccentric distance on the vertical direction of excitation, and analysis their impact on the seismic pounding response.