单层连方型球面网壳与下部支承结构协同工作的强震失效研究

基于ABAQUS有限元分析,研究了单层连方型球面网壳结构在90种工况下的3种失效模式:弱支承结构失效模式、强支承结构失效模式和中等支承结构失效模式。不同失效模式下结构所能承受的极限加速度有较大差别。结构处于弱支承或强支承状态时失效极限荷载较低,处于中等支承时失效荷载较高;在由弱或强支承向中等支承过渡的区间,结构的失效荷载呈现逐渐增加的趋势。当上下部结构刚度比较匹配时,二者才能充分发挥抗震性能,同时结构的极限承载力也会相对较高。下支承柱刚度是影响结构失效模式和极限荷载的主要因素之一,研究结果表明,随着支承刚度的增加,结构极限荷载呈先增加后减小的趋势。随着屋面等效荷载的增加,结构的极限承载力将会降低,在地震中更容易发生破坏。

Failure Modes of Single-layer Lamellar Spherical Reticulated Shellsunder Cooperative Work with Lower SupportingStructures and Severe Earthquakes

This paper proposes three structural failure models of single-layer lamellar spherical reticulated shells under 90 working conditions based on ABAQUS finite element analysis; these models include the failure modes of weakly supported structures, strongly supported structures, and moderately supported structures. The ultimate acceleration of the structure markedly differs under different failure modes, and the ultimate failure loads of the structure under the failure modes of weak and strong support are low, while that under the failure mode of moderate support is relatively high. The failure load of the structure presents an increasing trend in the interval from weak or strong support to medium support. When the stiffness of the upper and lower structures is matched, the ultimate bearing capacity of the structure is relatively high. The stiffness of the lower supporting columns is one of the main factors affecting the failure modes and ultimate loads of a structure. Increases in supporting stiffness cause the ultimate load of the structure to first increase and then decrease. As the equivalent load of the roof increases, the ultimate bearing capacity of the structure decreased and shows greater potential to be damaged in an earthquake.