凯威特型单层球面网壳在强震下的失效研究

动力强度破坏是网壳结构在遭受地震时的主要失效形式,准确的失效判别需要以基于材料损伤理论的分析为基础。为在动力时程分析中考虑材料损伤累积的因素,编制了基于有限元软件ABAQUS的用户材料子程序,具有较高的计算精度和较好的收敛性,实现了网壳结构考虑材料损伤的动力有限元分析。对单层球面网壳在强震下的失效特点进行了系统的参数研究,探讨了考虑材料损伤因素对网壳失效特征的影响;综合网壳失效时刻的多项特征响应,拟合了能够评估网壳动力损伤程度的损伤模型;基于损伤模型表示的网壳极限状态的物理意义,建立了适用于跨度40m的凯威特单层球面网壳强震失效判别准则,可用之判定网壳在强震作用下的失效极限荷载。

SEISMIC FAILURE OF SINGLE-LAYER RETICULATED DOMES

The dynamic strength failure is the main seismic failure mode of single-layer reticulated shells, and the prediction of failure load requires the consideration of material damage cumulation. A material subroutine in the platform of ABAQUS is developed for analyzing reticulated shells subjected to dynamic loads considering damage cumulation. Then, the failure behavior of single-layer reticulated domes under severe earthquakes is investigated, and the effect of damage cumulation is discussed. According to characteristic responses of single-layer reticulated domes at the failure state, the explicit definitions of failure states are established, and the strength failure criterion is proposed.