结构可靠度的显式迭代算法

EXPLICIT ITERATION ALGORITHM OF STRUCTURAL RELIABILITY

基于结构可靠性设计中的改进的一次二阶矩法,提出一种可靠度的显式迭代算法,该算法能够避免原有方法需要解方程计算可靠度指数β的缺点,具有简便的计算形式,利于编程实现。对于在可靠度计算中存在的无法等效为正态分布问题,提出一种近似解决方法。在此基础上,提出利用显式迭代算法和通用有限元软件计算结构可靠度的方法,且能够完全考虑材料、结构尺寸和载荷等随机因素的影响,而不必采用概率有限元法计算应力的统计特性。3个算例的结果验证了显式迭代算法的正确性。

Based on the modified first order second moment method （MFOSM） of structural reliability, an explicit iteration algorithm is proposed, which can avoid solving struatural performance function to get reliability index β and is very convenient for computer programme. An approximate method resolving the problem that non-normal random variables can not be equivalent to normal distribution is also put forward. Then how to use the explicit iteration algorithm and general finite element method（FEM） software to calculate reliability is demonstrated, in which the effect of some random factors such as ma- terial, dimensions, loads, etc, can be logically considered and probability finite element method（PFEM） is unnecessary. The validity of the explicit iteration algorithm is illustrated through three examples finally.