A general procedure for first/second-order reliabilitymethod (FORM/SORM)
A general procedure for first/second-order reliabilitymethod (FORM/SORM)
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DOI：
10.1016/s0167-4730(99)00008-9
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发表时间：
1999-06
影响因子：
5.8
通讯作者：
Yan-Gang Zhao;T. Ono
中科院分区：
文献类型：
--
作者：
Yan-Gang Zhao;T. Ono
一/二阶可靠度法（FORM/SORM）被认为是最可靠的结构可靠度计算方法之一。其精度一般取决于三个参数，即设计点曲率半径、随机变量数量和一阶可靠度指标。本文研究了FORM/SORM能准确反映的三个参数的取值范围。结果可以帮助我们判断什么时候FORM足够精确，什么时候需要SORM，什么时候需要精确的方法，如快速傅里叶反变换（IFFT）方法。提出了FORM/SORM的一般程序，该程序包括三个步骤：极限状态曲面的点拟合、主曲率和k的计算以及根据k的取值范围计算失效概率。通过几个例子说明了这个过程。
First/second-order reliability method (FORM/SORM) is considered to be one of the most reliable computational methods for structural reliability. Its accuracy is generally dependent on three parameters, i.e. the curvature radius at the design point, the number of random variables and the first-order reliability index. In the present paper, the ranges of the three parameters for which FORM/SORM is accurate enough are investigated. The results can help us to judge when FORM is accurate enough, when SORM is required and when an accurate method such as the inverse fast Fourier transformation (IFFT) method is required. A general procedure for FORM/SORM is proposed which includes three steps: i.e. point fitting limit state surface, computation of the sum of the principal curvatures Ksand failure probability computation according to the range of Ks. The procedure is demonstrated by several examples.