非概率可靠性指标空间搜索算法

考虑不确定参数为区间变量，研究求解非概率可靠性指标的空间搜索算法。针对功能函数呈非线性性态的特征，采用切平面与G=0平面交线对非线性功能函数进行线性化处理，利用等倾线与等效线性功能函数的交点确定迭代点。经优化搜索，当功能函数取0值时，确定了最可能失效点，进一步确定非概率可靠性指标。经数值算例验证了本文提出的优化搜索算法具有较高的搜索效率，与相关结果比较验证了算法的正确性。

Optimal searching algorithm for non-probabilistic reliability

With the consideration of interval variables as uncertain parameters,the paper emphasizes the iterate algorithm of optimal searching path in order to get non-probabilistic reliability index. For the case of the non-linear performance function,the intersection line of the tangent plane and G=0 was achieved so as to linearize the performance function. The intersection point as an iterate point was determined by isocline and equivalent linear performance function. The most probable failure point (MPP) was obtained when G=0 after optimal searching. Furthermore,the reliability index could be calculated according to MPP. Two numerical examples were applied for testing and verifying the proposed algorithm and good agreement was achieved.