【作者】 郭端祥； 黄慎江；

【Author】 GUO Duanxiang;HUANG Shenjiang;School of Civil and Hydraulic Engineering, Hefei University of Technology;Anhui Key Laboratory of Civil Engineering Structures and Materials;

【机构】 合肥工业大学土木与水利工程学院； 土木工程结构与材料安徽省重点实验室；

【摘要】 为研究双层椭球面网壳在地震作用下的抗震性能与失效机理,以某中学体育场作为分析对象,选取20组三向地震动,运用SAP2000有限元软件对结构进行增量动力分析。考虑底部混凝土框架协同作用,选用层间位移角、节点挠跨比和杆件屈服比例作为损伤指标综合评价整体结构的地震倒塌性能。基于IDA分析结果,对多组地震动下网壳结构的不同破坏特征进行失效机理分析,得到两种倒塌破坏模式。对地震峰值加速度和不同损伤指标结果进行回归分析,得到单独结构和整体结构的易损性曲线。研究表明,双层网壳的在地震作用下主要表现出突发性的整体失稳破坏与塑性积累超限的动力强度破坏;在三向地震动输入下,底部框架的抗震性能要优于双层网壳,对结构整体结构进行抗震性能评价时不宜忽视网壳损伤产生的影响。更多还原

【Abstract】 In order to study the seismic performance and failure mechanism of double-layer ellipsoidal mesh shell under seismic action, this paper takes a middle school stadium as an analytical object, and uses SAP2000 finite element software to perform incremental dynamic analysis by selecting 20 groups of three-directional ground shaking.Considering the synergistic effect of the concrete frame at the bottom, the analysis selects the inter-story displacement angle, node deflection-to-span ratio and rod yield ratio as the damage indicators to evaluate the seismic collapse performance of the overall structure comprehensively. Based on the results of IDA analysis, we found two collapse damage modes by analyzing the failure mechanism of different damage characteristics of the mesh shell structure under multiple sets of ground shaking. Meanwhile, the susceptibility curves of the individual structure and the overall structure are obtained by regression analysis of the peak seismic acceleration and the results of different damage indicators. It is shown that the double-layer mesh shell mainly exhibits sudden overall instability damage and bar strength damage with plastic accumulation exceeding the limit under seismic action. The seismic performance of the bottom frame is better than that of t he double-layer mesh shell under three-way ground shaking input, and it is not appropriate to neglect the effect of mesh shell damage when evaluating the seismic performance of the structure as a whole.更多还原