基于可靠度的单层网壳稳定设计方法

基于可靠度的钢结构稳定设计理论,提出了通过抗力分项系数验算网壳结构稳定性的方法。在确定分项系数时,分别考虑了材料、几何初始缺陷和计算模式的不确定性,使用基于响应面函数的蒙特卡罗模拟方法对结构进行二阶弹塑性分析。首先对两个网壳试验模型的试验结果做了数值分析对比,验证了本文有限元模型的有效性。然后选择应用最广的K8作为重点对象,使用基于响应面函数的蒙特卡罗模拟方法对结构进行考虑初始缺陷的二阶弹塑性分析,得出了抗力分项系数。

Design method for latticed shells based on reliability theory

The stability design for steel latticed shells is proposed based on the reliability theory.In this design method the nonlinear analysis is carried out and the system resistance factor of structures is suggested in order to check the stability.The second-order inelastic analysis,considering material,geometric imperfections and uncertainty of calculation mode,is carried out to obtain the limit load.In addition,the Monte Carlo simulation on the response surface is applied to statistical study of the resistant factor.Firstly,model validation via uncertainty propagation using response surface models is used.Secondly,for K8 latticed shells,the second-order inelastic analysis,considering material and geometric imperfections,is carried out to obtain the limit load.Finally, the Monte Carlo simulation on the response surface is applied to statistical study of the resistant factor.