结构可靠度分析中的改进响应面法及其应用

AN IMPROVED RESPONSE SURFACE METHOD FOR STRUCTURAL RELIABILITY ANALYSIS AND ITS APPLICATION

  • 摘要: 在以响应面法分析结构可靠度中,提出了一种区别于通常以插值点为中心展开生成样本点组的新方法:在求解过程中,用插值点逐步替代初始样本点组中距离验算点较远的点,目的是使所选取的样本点集中于真实极限状态曲面上的验算点附近,重新构成下一轮迭代所需的一组样本点,直至满足收敛条件。算例表明,采用新方法可使结构的分析次数显著减少,并改善了对非线性程度较高的极限功能函数求解可靠指标的收敛性。同时,将该方法应用于一座拟建自锚式斜拉-悬吊体系桥正常使用极限状态下的可靠度分析中。

     

    Abstract: The response surface method (RSM) for structural reliability analysis is improved by proposing a new strategy for positioning sampling points. In the new strategy, one of the initial sampling points that is the most far away from the interpolate point is replaced by the interpolate point generated in every iteration step, in order to make sampling points closer to the design point on the actual limit state surface. A new group of points are then established, and the strategy is performed in the next iteration process until the convergence condition is met. So, only one structural analysis is performed in every iteration step instead of 2n+1 structural analyses are needed to be performed in conventional RSM. Examples are given to demonstrate the advantages of the new method for both computation cost and the convergence of nonlinear limit function. And the reliability analysis for a self-anchored cable-stayed-suspension bridge planed to be built is performed under service limit states by the proposed approach.

     

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