数值模拟法分析薄壁箱梁的可靠性

在箱型梁剪力滞效应分析中一维离散分析的有限元法基础上,利用纽曼级数(Neumann Expansion)展开蒙特卡罗(Monte-Carlo)模拟方法,建立了考虑材料参数具有不确定性的薄壁箱型梁的计算模型,分析了箱梁的可靠度。将纽曼级数展式与箱型梁随机特性分析的一维离散蒙特卡罗有限元法相结合,从而避免了传统蒙特卡罗法在每一次随机抽样计算中都必须对总刚度方程进行分解计算的弊端,可以大大提高计算效率。算例结果表明,箱型梁一维离散的纽曼级数展开蒙特卡罗有限元法计算收敛速度快,精度高,可以满足工程应用要求。

Numerical simulation techniques for structural reliability analysis of box girders

Based on the one-dimensional FEM for the shear-lag effect of box girders and the Neumann Expansion Monte-Carlo simulation techniques,one dimensional discretized model was presented for structural analysis of box-girders with uncertainty.The stiffness matrix was decomposed once every time using the conventional Monte Carlo simulation method employed for statistic analysis,but it needn't decompose the stiffness matrix using the Neumann Monte Carlo method.It can obtain results with better efficiency and accuracy using the Neumann Monte Carlo method than the direct Monte Carlo method.