用不求导数的最优化计算可靠度指标

Applying the Optimization Method to Compute the Geotechnical Reliability Index without Derivation

本文从线性极限状态函数下独立正态分布变量的可靠度指标β的几何涵义出发,运用最优化计算原理,提出了不用导数计算β和设计验算点的优化分析方法。文中用改进Powell法研制的计算程序,避免了大多数可靠度分析法有时甚繁的求导数工作。通过对多个工程实例的可靠度分析表明,该方法使用方便、收敛快,计算精度不低于国际结构安全度联合委员会(JCSS)推荐采用的“JC”法。

Based on the geometric implication of the reliability index of the normally distributed uncorrelated variables the limit state function of which is linear, the paper introduces a method using the optimization principles to compute the reliability index, and applies powell method to work out a computer program which can directly compute the reliability index without derivation. The reliability of some engineering examples are analysed by the method, showing that the method is reliable and its accuracy isn't lower than that of the 'JC' method proposed by the Joint Committee on Structural Safety.