基于改进加权响应面的结构可靠度计算方法

Response surface method is a widely used agent model analysis method for structural reliability analysis because of its good applicability and maneuverability. Aimed at the difficulties of the response surface method, such as balancing the efficiency and accuracy, a structural reliability calculation method based on improved weighted response surface is proposed. In the iterative process, three weighting factors, including the distance between the sample point and the design point, the absolute value of limit state function and the value of joint probability density function, are considered to weight the sample points. The quadratic polynomial response surface function without cross term is updated by weighted regression and reusing all known sample points. After the iterative convergence, the sample points with the larger weight among the existing sample points are selected to fit the quadratic polynomial response surface function with cross terms. Finally, with numerical examples and engineering cases, the feasibility of the proposed method is verified by comparing with traditional sampling methods and other response surface methods. The results show that the proposed method has higher efficiency and meanwhile guarantees accuracy.