A Modification Method of Nonlinear Structural Finite Element Model Based on Complex Variable Differential Sensitivity

Abstract

The invention discloses a complex variable differential sensitivity-based nonlinear structure finite element model correction method, which comprises the following steps of firstly, establishing a nonlinear finite element initial analysis model of a structure; secondly, performing complex step perturbation on a to-be-corrected parameter in the structure, and calculating nonlinear dynamic responsesensitivity; thirdly, measuring response data of the structure, and establishing an objective function of nonlinear model correction; and finally, performing least square optimization on the measureddynamic response and the analyzed dynamic response so as to realize nonlinear finite element model correction, so that the structural parameters of the nonlinear finite element analysis model can be corrected, and the calculation precision of the analysis model is improved.

Description

technical field [0001] The invention belongs to the field of nonlinear structure finite element model correction, in particular to a nonlinear structure finite element model correction method based on complex variable differential sensitivity. Background technique [0002] The maturity of the finite element analysis method provides a fast and effective numerical solution for the analysis of engineering structures. However, the errors in the finite element modeling process often lead to the inability of the initial finite element model to accurately represent the mechanical characteristics of the structure. As a method to provide an accurate engineering structure analysis model, finite element model correction uses the measurement data of the analysis structure to modify the modeling parameters of the finite element analysis model, so that the residual error between the analysis response and the measurement dynamic response is minimized, thereby obtaining an accurate analysis...

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Problems solved by technology

[0003] The application of existing model correction technology in linear structures has been relatively mature, but the theory of nonlinear structural finite element model correction methods is still under development when considering the nonlinear characteristics of structures

Moreover, in the current nonlinear finite element model correction technology, the frequency domain response data of the structure and the non-gradient-based optimization algorithm are generally used to correct the finite element model of the nonlinear structure, which increases the analysis time.

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