基于马尔科夫链模拟的支持向量机可靠性分析方法

SUPPORT VECTOR MACHINE RELIABILITY ANALYSIS METHOD BASED ON MARKOV CHAIN SIMULATION

  • 摘要: 针对实际工程中可靠性分析设计的极限状态方程为隐式的情况,提出了一种基于马尔科夫链模拟的支持向量机可靠性分析方法。所提方法采用改进的马尔科夫链来产生极限状态重要区域上的样本点,再采用支持向量机方法求得相应的函数替代模型来进行可靠性分析。由于马尔科夫链能够自适应的模拟极限状态重要失效区域附近的样本,并且由于采用马尔科夫链备选样本点而非状态点作为训练样本,因而所提方法能够高效快速逼近对失效概率贡献较大区域的极限状态方程,并且充分利用了模拟过程产生的有用信息。所提方法还采用了一种渐变方差的模拟策略,改善了马尔科夫链模拟样本的质量。另外所提方法分别采用支持向量机分类方法和回归方法来构建函数替代模型,能够实现风险最小化的极限状态方程的替代,使得失效概率可以高效高精度地被逼近。最后给出了数值算例和工程算例,表明该文所提方法在计算效率和精度上具有较好的性能。

     

    Abstract: For the implicit limit state function usually encountered in an engineering reliability analysis and design, the Support Vector Machine (SVM) reliability analysis method is proposed on fast Markov chain simulation. In the proposed method, Markov chain is used to simulate the samples in the importance region defined by the limit state function, and the surrogate model is obtained by using these samples to train a SVM. Since Markov chain can adaptively simulate the samples of the importance region, and the candidate states but not Markov states are used as the training samples, the proposed method can well approximate the limit state equation in the region contributing to the failure probability significantly, and can utilize the information provided by Markov chain simulation sufficiently. In addition, the gradual change on variance in a simulation process is adopted to improve the quality of the Markov chain samples. Moreover, the proposed method uses the SVM regression method and classification method to construct the surrogate model, which can minimize the risk in approximating the limit state equation, and thus approximate the failure probability with a high precision. Finally numerical and engineering examples illustrate that the proposed method owns good performance in calculating efficiency and precision.

     

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