矿棉板吊顶碰撞响应试验研究OA

Pounding behavior is prone to occur at the boundary of suspended ceiling(SC)systems with mineral wool board during earthquakes,which has adverse effects on the seismic performance of the SC.Unidirectional pounding tests were conducted on four specimens of the SC with mineral wool board.The sinusoidal excitation was input to ceiling specimens via a high-speed horizontal actuator.The influence of the type of grid members occurring pounding,boundary condition,and frequency of input on collision responses of the ceiling system were systematically investigated.Experimental results show that the damage process and final failure patterns of the ceiling with different boundary conditions are basically the same.Grid connections are the weak points of the SC system,which are easy to first damage under collision behavior.The unseating of grid ends can be success-fully prevented by seismic clips installed at the semi-free boundary.Grid members are mainly subjected to com-pressive force,the strain of gird members near the ceiling boundary is relatively large but much smaller than the yield strain of the steel.As the input frequency increases,the collision speed increases accordingly.The influ-ence of pounding velocity on the pounding stiffness of grid members is not significant.The pounding stiffness of different types of grid members is different.Specifically,the pounding stiffness of grid members rises with the increase of their cross-sectional area.The boundary condition has insignificant effects on the pounding stiffness of grid members.Linear pounding model is developed to simulate the collision behavior.The model parameters are identified using genetic algorithm based on test results.The numerical simulation results agree well with ex-perimental results.The generic magnitudes for the pounding stiffness of grid members are proposed,which can provide reference for establishing an accurate finite element model for the SC system.