吊顶地震时程反应分析的二维简化模型

A Two-dimensional Simplified Model for Seismic Response History Analysis of Suspended Ceilings

吊顶是由各种轻钢龙骨、吊顶板、吊杆等构件拼装组成的松散的非连续体系,其地震反应的数值模拟尚缺乏研究。介绍一种用于吊顶地震反应分析的二维简化模型,能够模拟吊顶在沿主龙骨方向的水平地震作用和竖向地震作用下的动力反应,且能够考虑吊顶板与龙骨之间的摩擦、滑移、碰撞等因素的影响。利用该模型在OpenSees中模拟了由4块吊顶板组成的基本吊顶单元的双向加载振动台试验。通过对比试验和数值模拟得到的吊顶加速度反应的时程和傅里叶谱以及坠板率,验证了该二维简化模型的合理性。进一步,利用该模型考察了吊顶坠板率的频率相关性。结果表明,吊顶的坠板率不仅仅取决于楼面峰值加速度的大小,而是表现出显著的频率相关性。

The suspended ceiling is a flexible system composed of loosely connected light-gauge-steel runners,panels,hanger rods,etc.There is still a lack of research on the numerical simulation of its seismic response.This paper introduces a two-dimensional simplified model for response history analysis of suspended ceilings under combined horizontal and vertical earthquake excitation along the main keel direction.The friction,sliding and pounding between the ceiling panels and the runners are also included in the model.The model is implemented in OpenSees and is calibrated by a shake table test on a minimum suspended ceiling unit composed of four panels and a single hanger rod.The rationality of the presented model is verified by comparing the acceleration response time history,Fourier spectrum and the rate of the fallen panels of the suspended ceiling obtained by experiments and numerical simulation.The model is further used to identify the engineering demand parameters that correlate with the extent of seismic damage in the suspended ceiling.The results show that the rate of the fallen panels not only depends on the peak floor acceleration,but also shows significant frequency-dependency.