主余震作用下不同货载工业货架的动力稳定性数值分析

Numerical analysis of dynamic stability of industrial racks with different loads under main-aftershocks

以10层8跨钢结构货架为例,基于地震设计反应谱挑选3组典型自然波并构造1组人工地震波作为主余震序列的输入,对常见的0.5、1.0、1.5、2.0 t托盘负载的货架进行非线性时间历程分析,以评估主余震环境下不同货载对货架结构抗震性能的影响。结果显示:峰值加速度较大的汶川地震波和Kocaeli地震波冲击可直接导致货载为1.0 t以上的货架在余震中倒塌;在长持时Chi-Chi地震波和人工地震波的主余震作用下,较大货载(2.0 t)的货架结构稳定性严重退化。综合结构模态振型以及层间位移角、结构件塑性铰程度等指标分析结果,在地震烈度为7度及以下的地震环境中,货载为1.5 t与M120A-B100工业货架适配时货架具有较好的抗震性能。

Taking 10-story 8-span steel shelves as an example,based on the seismic design response spectrum,three sets of typical natural waves were selected and one set of artificial seismic waves was constructed as the input of the main-aftershocks.The nonlinear time history analysis was conducted for racks with common 0.5,1.0,1.5,and 2.0 t pallet loads to evaluate the effects of different loads on the seismic performance of the rack structure under the main-aftershock environment.The results show that Wenchuan seismic wave and Kocaeli seismic wave with large peak accelerations can directly cause the collapse of racks with loads above 1.0 t in main-aftershocks;the structural stability of racks with larger loads(2.0 t)under the main-aftershocks of Chi-Chi seismic waves and artificial seismic waves with long holding times is severely degraded.The analysis of structural modal shapes,inter-story drift angle and the degree of plastic hinge of the structural members shows that the racks have good seismic performance when adapted to the M120A-B100 industrial racks with a load of 1.5 t under the seismic environment with seismic intensity of 7 degrees or less.