双层球面网壳的序列地震效应敏感性研究

为了研究双层球面网壳结构响应对于序列地震是否敏感、避免结构在主震后的余震作用下发生倒塌,首先建立了基于通用有限元软件ABAQUS的结构有限元模型,并对太平洋地震工程研究中心(PEER)数据库中的主余震序列地震动数据进行了筛选,共收集到342对主余震序列地震动时程数据;利用全荷载域动力时程分析方法,获得了各序列地震作用下结构的特征响应随加速度幅值的变化规律,归类并定义了网壳结构多重地震效应的四种影响程度;然后,对大量算例的结果进行统计,得到了在主震结束时的网壳特征响应(最大节点位移、屈服杆件比例和结构损伤因子)与结构抵抗余震能力的关系;最终将屈服杆件比例作为衡量双层球面网壳抵抗余震能力的指标,并给出了各跨度双层球面网壳屈服杆件比例的敏感界限值。研究成果可为网壳结构的抗震设计及抗震性能评估提供参考。

Sensitivity of sequence seismic effects of double-layer reticulated domes

To study whether or not structural responses of double-layer reticulated domes was sensitive to sequence earthquake to avoid structure collapse under aftershocks, a structure’s finite element model was established based on the finite element software ABAQUS.Data of main shock and aftershock responses to sequence earthquake in database of the pacific earthquake engineering research center (PEER) were selected to collect 342 groups of main shock and aftershock acceleration response time histories data.The dynamic time history analysis method in full load domain was adopted to obtain variation laws of structural characteristic responses with changes of acceleration amplitude under various sequence earthquakes.4 effect levels on reticulated shell structures’ multiple seismic responses were classified and defined.Then, statistic analysis was done for a lot of example results to obtain the relation between reticulated shells’ characteristic responses of maximum nodal displacement, proportion of yield members and structural damage factor when main shock was over and structures’ anti-aftershock ability.Finally, the proportion of yield members was taken as the index to measure double-layer reticulated domes’ anti-aftershock ability, and sensitive limit values of proportion of yield members for double-layer reticulated domes with different spans were given.The study results provided a reference for aseismic design and aseismic performance evaluation of reticulated shell structures.