Improving the reliability of the frequency response function through semi-direct finite element model updating

2016 ◽  
Vol 54 ◽  
pp. 59-71 ◽  
Author(s):  
Jae Hyuk Lim ◽  
Do-Soon Hwang ◽  
Dongwoo Sohn ◽  
Jin-Gyun Kim
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Model Updating ◽  
Element Model ◽  
Finite Element Model Updating

scholarly journals Frequency-based decoupling and finite element model updating in vibration of cable–beam systems

2021 ◽  
pp. 107754632199693
Author(s):  
Mohammad Hadi Jalali ◽  
D. Geoff Rideout
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Model Updating ◽  
Element Model ◽  
Finite Element Model Updating ◽  
Response Functions ◽  
Modal Properties

Interactions between cable and structure affect the modal properties of cabled structures such as overhead electricity transmission and distribution line systems. Modal properties of a single in-service pole are difficult to determine. A frequency response function of a pole impacted with a modal hammer will contain information about not only the pole but also the conductors and adjacent poles connected thereby. This article presents a generally applicable method to extract modal properties of a single structural element, within an interacting system of cables and structures, with particular application to electricity poles. A scalable experimental lab-scale pole-line consisting of a cantilever beam and stranded cable and a more complex system consisting of three cantilever beams and a stranded cable are used to validate the method. The frequency response function of a cantilever (“pole”) is predicted by substructural decoupling of measured cable dynamics (known frequency response function matrix) from the measured response of the assembled cable–beam system (known frequency response function matrix). Various amounts of sag can be present in the cable. Comparison of the estimated and directly obtained pole frequency response functions show good agreement, demonstrating that the method can be used in cabled structures to obtain modal properties of an individual structural element with the effects of cables and adjacent structural elements filtered out. A frequency response function–based finite element model updating is then proposed to overcome the practical limitation of accessing some components of the real-world system for mounting sensors. Frequency response functions corresponding to inaccessible points are generated based on the measured frequency response functions corresponding to accessible points. The results verify that the frequency response function–based finite element model updating can be used for substructural decoupling of systems in which some essential points, such as coupling points, are inaccessible for direct frequency response function measurement.

Finite Element Model Updating Using Frequency Response Function of Incomplete Strain Data

AIAA Journal ◽  
2010 ◽  
Vol 48 (7) ◽  
pp. 1420-1433 ◽  
Author(s):  
Akabr Esfandiari ◽  
Masoud Sanayei ◽  
Firooz Bakhtiari-Nejad ◽  
Alireza Rahai
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Model Updating ◽  
Element Model ◽  
Finite Element Model Updating ◽  
Strain Data

The Study and Application of Electromagnetic Vibration Shaker Finite Element Model Updating and Validation Technology

2010 ◽  
Vol 458 ◽  
pp. 231-236
Author(s):  
Xun Tao Liu ◽  
Zhao Bo Chen ◽  
Li Fu Xu ◽  
Shan Yun Huang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Model Updating ◽  
Element Model ◽  
Model Parameters ◽  
Electromagnetic Vibration ◽  
Vibration Shaker

Acording to the fact that the finite element model of electromagnetic vibration shaker for virtual experiment is not accurate enough to complete accurately spacecraft test, made a correlation analysis of the finite element output frequency response function and the measured frequency response function by their correlation coefficients. Analyzed the sensitivity of the materials for FRF and screened the parameters to update, made the correlation coefficient error of electromagnetic vibration shaker finite element model frequency response function and the measured as the optimization objective, the optimization and modification of shaker finite element model parameters were completed by iteration method. The frequency response function of the modified finite element model approximately agreed with the experimental frequency response function. It met the virtual experiments of electromagnetic vibration shaker.

scholarly journals Frequency Response Function-Based Finite Element Model Updating Using Extreme Learning Machine Model

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yu Zhao ◽  
Zhenrui Peng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Frequency Response ◽  
Extreme Learning Machine ◽  
Surrogate Model ◽  
Frequency Response Function ◽  
Model Updating ◽  
Element Model ◽  
Finite Element Model Updating ◽  
Learning Machine

A frequency response function- (FRF-) based surrogate model for finite element model updating (FEMU) is presented in this paper. Extreme learning machine (ELM) is introduced as the surrogate model of the finite element model (FEM) to construct the relationship between updating parameters and structural responses. To further improve the generalization ability, the input weights and biases of ELM are optimized by Lévy flight trajectory-based whale optimization algorithm (LWOA). Then, LWOA is also applied to obtain the best updating results, where the objective function is defined by the difference between analytical FRF data and experimental data. Finally, a plane truss is used to demonstrate the performance of the proposed method. The results show that, compared with second-order response surface (RS), radial basis function (RBF), traditional ELM, and other optimized ELM, a LWOA-ELM model has higher prediction accuracy. After updating, the FRF data and frequencies have a significant match to the experimental model. The proposed FEMU method is feasible.

Machine Gun Finite Element Model Amending Based on Frequency Response Functions of Vibration

2014 ◽  
Vol 599-601 ◽  
pp. 349-352 ◽  
Author(s):  
Ben Li Wang ◽  
Zi Wei Dong
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Model Updating ◽  
Element Model ◽  
Correction Method ◽  
Modal Testing ◽  
Model Correction

Correction machine gun finite element model to predict dynamic characteristics is very important. Through theoretical calculations and experimental test structure to obtain guns frequency response function, given the sensitivity of both the correlation function and expression, introduced a model correction method, and laid the theoretical foundation for a certain type of machine gun finite element model updating. Build a certain type of machine guns and modal testing and analysis system was carried out to test the vibration frequency response function. Boundary condition parameters of the machine gun was amended, and modal test results were compared to prove the validity of the model correction method.

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