Structural reliability method based on dynamic weight response surface under mixed uncertainty

Abstract

The invention discloses a structural reliability method based on dynamic weight response surface under mixed uncertainty. The invention is applied to the field of reliability technical field, and aimsat structural reliability problems under mixed variables. The method comprises the following steps of determining a fitted sample of a current iterative response surface; fitting and getting the response surface of the current iteration by weighted least squares; getting the reliability design point of the current response surface according to the hybrid variable decoupling method; stopping the iteration, when the value of the random variable part of the reliability design point obtained by two adjacent iterations satisfies the convergence criterion; calculating the failure probability of thestructure by Monte Carlo simulation according to the response surface obtained from the last iteration. The invention constructs the response surface, so that the limit state function in the standardnormal space is explicitly approximated in the form of a quadratic response surface, which facilitates subsequent reliability analysis. And a double weighting mechanism is introduced to effectively improve the accuracy and computational efficiency of the response surface method.

Description

technical field [0001] The invention belongs to the field of reliability engineering, in particular to a structural reliability analysis technology based on a dynamic weight quadratic response surface under mixed uncertainties. Background technique [0002] With the development of the times, the complexity and reliability requirements of various engineering structures are constantly increasing. Engineering structures are inevitably disturbed by various uncertain factors (such as material properties, external loads, and geometric dimensions) during operation, which makes the response of key nodes of the structure uncertain. In traditional engineering design, the safety factor is used to ensure the relative stability of the designed structure, and the ratio of the expected strength response of the structure to the expected load is usually used as the safety factor value. Obviously, the traditional method does not consider the uncertainty of each influencing factor. At the sa...

AI Technical Summary

Problems solved by technology

However, the existing dynamic quadratic response surface algorithm is usually only applicable to the system with random variables, but not to the system with both random and interval mixed variables; in addition, the dynamic quadratic response under the existing mixed variables The surface method does not consider the weight of the test sample in the iterative process, and the accuracy and efficiency of the algorithm are low

Images