Detection of structural damages by model updating based on singular value decomposition of transfer function subsets

2020 ◽  
Author(s):  
Mohammad Rahai ◽  
Akbar Esfandiari ◽  
Ali Bakhshi
Keyword(s):  
Transfer Function ◽  
Singular Value Decomposition ◽  
Model Updating ◽  
Singular Value ◽  
Value Decomposition

Vibration load and transfer path identification of vehicle using inverse matrix method based on singular value decomposition

2019 ◽  
Vol 234 (6) ◽  
pp. 1703-1713
Author(s):  
Chao Yang ◽  
Yansong Wang ◽  
Hui Guo ◽  
Jiang Lv ◽  
Ningning Liu ◽  
...  
Keyword(s):  
Transfer Function ◽  
Singular Value Decomposition ◽  
Condition Number ◽  
Singular Value ◽  
Reference Points ◽  
Load Identification ◽  
Transfer Function Matrix ◽  
Key Points ◽  
Value Decomposition ◽  
Function Matrix

Based on the theory of inverse transfer matrix, a novel method for simultaneous load identification of vehicle vibration is presented in this paper. Some response, excitation, reference points (called key points) and their transfer paths, which have severe effects on the vibration of a whole vehicle, are defined. The transfer functions among the key points are measured by experiments, and thereby a transfer function matrix of vehicle vibration is established. To solve ill-conditioning problem in the transfer function matrix, the methodology of singular value decomposition is introduced into matrix inversion in the excitation load identification. To reduce the identification error, four transfer function matrices with different reference points and condition numbers are selected and discussed. The results show that the more the reference points are, the smaller the condition number of transfer function matrix is, the higher the accuracy of excitation load identification. The transfer function matrix with minimum condition number is used to identify the excitation loads at the vehicle key points. Experimental verifications suggest that the newly proposed method is effective and feasible for excitation load identification of vehicle vibration. Using the identified excitation loads, furthermore, the vibration causes of the steering wheel and seat rail are obtained, which is helpful for improving vibration performance of the sample vehicle. In applications, the excitation load identification method proposed in this paper may be applied not only to other types of vehicle, but also to other complex electromechanical products for load identification in engineering.

A Singular-Value Decomposition Method for Updating the Analytical Model

1997 ◽  
Author(s):  
Zhang Xianmin
Keyword(s):  
Singular Value Decomposition ◽  
Analytical Model ◽  
Model Updating ◽  
Large Error ◽  
Singular Value ◽  
Approximation Technique ◽  
Model Parameters ◽  
Matrix Approximation ◽  
Approximation Solution ◽  
Value Decomposition

Abstract Based on the theory of singular-value decomposition and the matrix approximation technique, an analytical model updating method using the identified model parameters is developed. Firstly, The identified modal matrix is decomposed by means of singular-value decomposition technique. The general updating equations for the analytical model are obtained according to the decomposition results, the eigenequation of the system, and the modal orthogonality relations. Secondly, the best matrix approximation solution for the updating equations is definited. The existence and uniqueness of the best approximation relative to the analytical model are studied. The concrete form of the best modification and two algorithms are presented. Examples demonstrate that the analytical model modification method developed in this paper possesses high modificatory accuracy comparing with some other methods. The method possesses the ability to modify the large error models.

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