Finite element algorithm for decoupling unsteady vibration based on complex domain eigenvalue and application process

Abstract

The invention relates to a finite element algorithm for decoupling unsteady vibration based on a complex domain eigenvalue and an application process, and the finite element algorithm is characterized in that the finite element algorithm carries out complex domain solution on a time domain vibration differential equation through Laplacian transformation, and the solution becomes matrix calculation with Laplacian variables as eigenvalues. When a calculation result captures a complex domain characteristic value, the complex domain characteristic value is essentially a vibration mode causing an unstable system response to be deduced, and then essential reasons of automobile structure vibration and braking howling are revealed. The finite element algorithm for decoupling the unsteady vibration through the complex domain eigenvalue and the application process of the finite element algorithm are applied to the field of finite element numerical calculation of automobile structure design, good calculation efficiency and precision are achieved, the unsteady vibration mode can be reasonably predicted and decoupled, and the actual application level is achieved.

Description

technical field [0001] The invention relates to the field of computational mechanics, in particular to a finite element algorithm and an application process for decoupling unsteady vibrations based on complex domain eigenvalues. Background technique [0002] With the continuous application and development of numerical finite element simulation in the engineering field, the size of the designed product is getting bigger and bigger, and the structure is getting more and more complex. This complex structure is very susceptible to vibration due to the external and frictional coupling excitation force of the structure itself. In the design of automotive products, it will produce strong braking noise and steering wheel vibration, which will affect the use and cause customer complaints. Therefore, many automotive structural designs need to adopt measures such as changing structural design parameters to change the system excitation characteristics and decouple the vibration of the u...

AI Technical Summary

Problems solved by technology

In the general finite element algorithm, although there are matrix algorithms related to eigenvalues, such as power method, subspace iteration method, Lanczos method, QR method, Newton method, Jacobi method, etc., which are available for users to choose, but its calculation principle, It is difficult for general users such as application scenarios to understand and make correct choices

[0003]In the structural design of automobile engineering, complex structures and excitation characteristics are often involved, so it is necessary to synthesize the characteristics of matrix dimension, solution accuracy, and stiffness matrix sparseness and singularity In order to ensure that the algorithm and its program have high precision and fast convergence speed, the current general finite element algorithm adopts the method of selecting or specifying the default eigenvalue solver by conventional users, which often cannot meet the solving needs of ordinary users. Limits the application of complex-domain eigenvalue algorithms for decoupling unsteady vibrations

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