【摘要】 以平面30 m×30 m,矢跨比分别为1/6,1/7,1/8和1/9的椭圆抛物面单层网壳为对象,利用ANSYS非线性动力软件,研究其弹塑性动力失稳。计算中考虑几何和材料非线性效应,并对几何缺陷、阻尼、不同地震波及其输入方向等对稳定性的影响进行了分析。结果表明:该结构的动力失稳一般伴随着较大的塑性变形,具有明显的突发性;在水平地震作用下动力稳定临界荷载明显低于竖向地震作用下的临界荷载,以两向地震作用下最低;在水平地震作用下,较大矢跨比时动力稳定临界荷载较低;杆件截面的增大可显著提高该结构的水平刚度和动力稳定临界荷载;几何缺陷能显著降低网壳结构的动力稳定临界荷载;考虑Raleigh阻尼模式,其临界荷载提高不足7%。更多还原

【Abstract】 This paper is focused on the dynamic buckling of the single layer reticulated domes under earthquake.The computation model is a single-layer elliptical parabolic latticed shell with 30 m×30 m of plane size and 1/6,1/7, 1/8 and 1/9 of the rise-span ratios.Detailed analysis is done on its elasticplastic buckling through ANSYS.The influences of both geometric and materials nonlinearity are within consideration.The results show that the buckling occurs abruptly with the larger plastic deformation accompanying;the dynamic buckling critical load under horizontal earthquake is larger than that under the vertical earthquake,and the dynamic buckling critical load under horizontal and vertical earthquake simultaneously is smallest;the dynamic buckling critical load of the shell with larger rise-span ratios under horizontal earthquake is lower;the increasing of the cross section areas of the shell bars result in the increasing of its dynamic buckling critical load under horizontal earthquake;the geometric imperfects cause the reducing greatly of the critical loads;the critical load is increased by less than 7% when the Raleigh damp is taken into consideration.更多还原