Finite element model correction method based on perturbation method for complex model under uncertainty

Abstract

The invention provides a finite element model correction method based on the perturbation method for a complex model under uncertainty, comprising: deducing an iteration form for average and covariance matrixes for under-correction parameters of the complex model; determining complex model correction target average and covariance matrixes; determining initial estimated values of the under-correction parameters of the complex model; calculating a sensitivity matrix and modal frequencies for the under-correction parameters of the complex model through finite element analysis; reading finite element calculation results of the complex model, and calculating an intermediate variable conversion matrix and the covariance matrix; correcting an average and covariance of the under-correction parameters of the complex model to obtain updated parameters; performing cyclic iteration to carry out parameter correction. File reading-writing and data transmission channels are established based on the commercial mathematical software MATLAB and the finite element simulation software NASTRAN; the method is suitable for solving model correction problems where both system parameters of a complex modeland test data present uncertainty, and corrected parameters have high average precision.

Description

technical field [0001] The invention relates to an uncertainty finite element model correction method, in particular to a complex model uncertainty finite element model correction method based on a perturbation method. Background technique [0002] Accurate structural dynamic model is the premise of dynamic response prediction, mechanical environment prediction, damage detection and dynamic optimization design. In recent decades, model correction technology has developed rapidly as an effective method to establish accurate dynamic models, and has been widely used in the engineering field to improve the correlation between finite element models and experimental data, and to improve the analysis accuracy and reliability of finite element models. [0003] The traditional finite element model correction only uses the data of a certain test to correct the initial finite element model, and there are many methods at present. However, there are generally two types of uncertainties ...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to overcome the deficiencies in the prior art, propose a kind of complex model uncertainty finite element model correction method based on the perturbation method, based on commercial mathematics software MATLAB and finite element simulation software NASTRAN, set up file reading and writing and data The transmission channel; it is suitable for solving the model correction problem where the system parameters and test data of the complex model have uncertainties, and the average precision of the corrected parameters is high

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