Load is one of the main causes of structural failure, and the correlation among loads would affect the evaluation results of structural performance. The purpose of this paper is to analyze the influence of the correlation among multiple loads on the structural reliability. In this paper, the nonparametric kernel density estimation (NKDE) method is used to estimate the probability density function (PDF) of related loads. In addition, the mixed copula (M-Copula) model is proposed, which combines Gumbel copula, Frank copula, Clayton copula, and weight coefficient, and the model parameters are fitted by MATLAB software to get the correlation of related loads. The reliability based on the related load combination is calculated according to the constructed model. After analyzing three numerical cases, the results show that the probability characteristics of NKDE estimation are very close to the actual conditions, and the reliability calculated by the M-Copula model is larger than those calculated by JCSS, Turkstra, and Gong methods. Using the M-Copula model for load correlation would avoid underestimating the reliability of the structure, which is conducive to structural economic development.

中文翻译：

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基于M-Copula的随机载荷相关性可靠性分析

载荷是结构破坏的主要原因之一，载荷之间的相关性会影响结构性能的评估结果。本文的目的是分析多种载荷之间的相关性对结构可靠性的影响。本文采用非参数核密度估计（NKDE）方法估计相关载荷的概率密度函数（PDF）。此外，提出了一种混合模型（M-Copula），该模型结合了Gumbel copula，Frank copula，Clayton copula和权重系数，并通过MATLAB软件对模型参数进行拟合，以获得相关载荷的相关性。根据所建立的模型计算基于相关载荷组合的可靠性。在分析了三种数值情况后，结果表明，NKDE估计的概率特征与实际情况非常接近，M-Copula模型计算的信度大于JCSS，Turkstra和Gong方法计算的信度。使用M-Copula模型进行荷载关联可避免低估结构的可靠性，这有利于结构经济的发展。