强震作用下双层球面网壳结构非线性动力响应分析

针对大跨网壳结构的动力特性,提出了在强烈地震作用下双层球面网壳结构的非线性分析和结构动力稳定性判别方法.单元模型中考虑几何非线性和材料非线性的双重影响.分析时,以静力荷载作用下的受力状态作为时程分析的初始状态,采用B-R判断准则确定其临界荷载,通过加速度峰值-结构最大位移曲线来判别结构的动力稳定性,据此找出其动力失稳临界点及破坏规律.通过算例验证了本文方法的有效性.分析结果表明,双层球面网壳结构考虑双重非线性是必要的;一致缺陷模态对结构承载力的影响比振型模态缺陷的影响大.

Nonlinear Analysis of Double-Layer Reticulated Spherical Dome under Strong Earthquake Motions

Based on the dynamic behavior of large span reticulated spherical dome,some methods were proposed for the nonlinear analysis and the dynamic stability behavior of double-layer reticulated spherical dome under strong earthquake motions.Both geometrical nonlinearity and elastoplastic were considered in the element model.The static loads were regarded as the initial condition in the nonlinear time-history analysis.Budiansky-Roth's criterion was used to judge the critical load,and through the curve of the largest displacement vs.the peak value of acceleration,we could find the dynamic stability behavior and the failure rules.Examples were given to prove that the methods were effective.The analysis result shows that it is necessary to consider both geometrical nonlinearity and elastoplastic,and that the effect of the modality of the uniform imperfection upon the bearing capacity of structure is bigger than that of vibration mode shape.