典型承压结构塑性失效概率密度函数计算方法研究

Typical Pressure Bearing Structures Plastic Failure PDF Computation Method

本文针对承压结构在内压载荷作用下的塑性失效概率密度函数计算方法进行了研究.基于可靠性分析中的蒙特卡罗法,设计了塑性失效概率密度函数计算程序.该程序可在结构多种参量为已知分布的随机变量的情况下,通过仿真计算,给出结构基于极限载荷分析的塑性失效概率密度曲线.以理想弹塑性材料内压圆筒为研究对象,基于分布函数法推导了其在壁厚及屈服强度均不确定情况下失效概率密度函数的理论解,并将其与仿真结果进行对比.结果表明:两种方法计算结果基本一致,且本文所提程序在进行多参数不确定耦合下塑性失效概率密度函数计算时,可大幅降低理论推导难度,具有一定的工程应用价值.

This study aims to investigate the plastic failure PDF computation method of typical pressure bearing structures under plastic limit load.A plastic failure PDF computer program is designed based on Monte Carlo method.The plastic failure PDF based on limit load analysis can be obtained with this simulation program when some parameters of structures are uncertain.The theoretical PDF model of internal pressure cylinder is derived when thickness and yield strength of the cylinder are uncertain,then the theoretical model and simulation model are compared.The results show that these two methods are in agreement with each other.The plastic failure PDF computation program is not only simple and convenient,but also greatly reduces the difficulty of theoretical derivation when many paramcters of structures are uncertain.