A Calculation Method of Structural Sensitivity Based on Acceleration Response

Abstract

A method for calculating structural sensitivity based on acceleration response is provided. The method includes: an acceleration frequency response matrix is constructed, the first m-order modal frequencies are obtained, a stiffness perturbation term is added from the first node of the structure, the acceleration frequency response matrix is substituted into the matrix correction formula to obtainthe acceleration frequency response matrix after perturbation, the frequency of the structure is identified, the sensitivity of the structural modal frequency to the stiffness is obtained, and the corresponding sensitivity is obtained by changing the position of the stiffness perturbation point according to the node order, thus the sensitivity of the whole structural modal frequency to the stiffness is obtained. When the rigidity of the structure is perturbed, the matrix transformation formula is utilized without recalculating the finite element, and only the initial acceleration frequency response information is needed for numerical calculation to obtain the perturbed acceleration frequency response function, so the calculation efficiency is simplified and the need for finite element calculation is eliminated, and the method is more convenient. The fast calculation method of sensitivity to stiffness based on the acceleration frequency response function is realized, which has practical engineering significance.

Description

technical field [0001] The invention relates to a sensitivity analysis method, in particular to a structure sensitivity calculation method. Background technique [0002] Sensitivity analysis is a method to evaluate the rate of change of structural response characteristics due to changes in design variables or parameters. The sensitivity of structural systems is particularly important, and it is one of the main research directions in the field of computational mechanics and structural engineering. [0003] In practical applications, the sensitivity analysis of structures plays an important role in structure optimization, reliability evaluation, and parameter identification. According to the strategy, the methods can be divided into discrete methods and variational methods. Traditional sensitivity analysis methods generally need to perform finite element calculations again under perturbation, especially when the structure is soft and the number of finite elements is large, th...

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Problems solved by technology

Traditional sensitivity analysis methods generally need to perform finite element calculations again under perturbation, especially when the structure is soft and the number of finite elements is large, the calculation amount is large and the efficiency is low

Acceleration signal measurement is relatively common. Sensitivity analysis such as stiffness parameters based on acceleration admittance information has become a practical engineering problem to be solved if the traditional sensitivity calculation efficiency is low.

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