网壳结构强震失效机理关键理论问题

随着大跨度网壳结构近些年在重大工程中的大量应用,其在强震下的失效机理这一基础理论问题也逐渐突出,为空间结构学者所关注。为此,总结了近些年在网壳结构强震失效机理领域的一些研究进展,介绍适用于网壳结构强震失效机理研究的基于多重响应的荷载域时程分析方法,阐述网壳结构在强震下的两类失效模式及其失效机理。在此基础上,对在网壳结构强震失效机理分析中的三个重要效应,即材料损伤累积效应、地震动空间变化性效应、下部支承结构影响,分别进行讨论及总结。

KEY THEORY OF FAILURE MECHANISM OF RETICULATED SHELLS SUBJECTED TO SEVERE EARTHQUAKES

With the application of large span reticulated shells in significant projects,the fundamental theory of failure mechanism of such structures subjected to severe earthquakes becomes more and more important and becomes one of the primary concerns of the researchers. It was summarized the research progress in the failure mechanism of large span reticulated shells under severe earthquakes in recent years. The analysis method reviewing full-range responses based on load domain was introduced. The two kinds of failure modes of reticulated shells,dynamic instability due to geometrical nonlinearity and the dynamic strength failure attributable to over-plastic damage accumulation,and their failure mechanism were presented. It was also proposed the dynamic damage model of reticulated shells and the determination methods of the ultimate load of reticulated shells subjected to severe earthquakes were summarized. Then,three important effects on failure mechanism for reticulated shells under earthquakes,the material damage accumulation,lower supporting structure and space change by seism were discussed.