单层组合网壳的双重非线性稳定问题

推导了梁元和三角形板壳元（ＤＫＴ元）在Ｕ．Ｌ．描述下的双重非线性切线刚度矩阵，对单层组合网壳结构进行了双重非线性稳定荷载－位移全过程跟踪分析，通过对增量形式虚功方程作线性化处理来减少计算量，采用施加线性弹簧法处理非正定切线刚度矩阵，用主，从节点考虑梁与板的耦合作用，分析了梁与板节点偏差的影响，并进行了实验对比研究。分析表明本文方法简便可行。

The Dual Nonlinear Stability Analysis of Single Layer Composite Reticulated Shell

The dual nonlinear tangent stiffness matrices of binodal spatial beam element and triangular plate/shell element of 6 nodal DOF to Update Lagrange coordinate systems are derived,and the complete dual nonlinear load displacement curve of a single layer composite reticulated shell is traced out by numerical analysis and model experiment. During the tracing, the incremental equation of virtual work is linearized to simplify calculation, and linear springs are applied to deal with the problem originated from non positive definite general tangent stiffness matrix; beam plate coupling, deviation of principal nodes and subordinated nodes are considered,including the initial defect of nodal location error.The results of theoretical and numerical analysis are compared with that of experiment,and some useful conclusions are obtained.