scholarly journals Transfer Learning Based Method for Frequency Response Model Updating with Insufficient Data

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5615
Author(s):  
Zhongmin Deng ◽  
Xinjie Zhang ◽  
Yanlin Zhao
Keyword(s):  
Finite Element ◽  
Feature Extraction ◽  
Finite Element Model ◽  
Frequency Response ◽  
Transfer Learning ◽  
Model Updating ◽  
Element Model ◽  
Insufficient Data ◽  
Comparison Results ◽  
Small Dataset

Finite element model updating precision depends heavily on sufficient vibration feature extraction. However, adequate amount of sample collection is generally time-consuming in frequency response (FR) model updating. Accurate vibration feature extraction with insufficient data has become a significant challenge in FR model updating. To update the finite element model with a small dataset, a novel approach based on transfer learning is firstly proposed in this paper. A readily available fault diagnosis dataset is selected as ancillary knowledge to train a high-precision mapping from FR data to updating parameters. The proposed transfer learning network is constructed with two branches: source and target domain feature extractor. Considering about the cross-domain feature discrepancy, a domain adaptation method is designed by embedding the extracted features into a shared feature space to train a reliable model updating framework. The proposed method is verified by a simulated satellite example. The comparison results manifest that sample amount dependency has prominently lessened this method and the updated model outperforms the method without transfer learning in accuracy with the small dataset. Furthermore, the updated model is validated through dynamic response out of the training set.

scholarly journals Model Updating Method Based on Kriging Model for Structural Dynamics

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Hong Yin ◽  
Jingjing Ma ◽  
Kangli Dong ◽  
Zhenrui Peng ◽  
Pan Cui ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Frequency Response ◽  
Structural Dynamics ◽  
Model Updating ◽  
Computational Cost ◽  
Element Model ◽  
Kriging Model ◽  
Surface Model ◽  
Sample Points

Model updating in structural dynamics has attracted much attention in recent decades. And high computational cost is frequently encountered during model updating. Surrogate model has attracted considerable attention for saving computational cost in finite element model updating (FEMU). In this study, a model updating method using frequency response function (FRF) based on Kriging model is proposed. The optimal excitation point is selected by using modal participation criterion. Initial sample points are chosen via design of experiment (DOE), and Kriging model is built using the corresponding acceleration frequency response functions. Then, Kriging model is improved via new sample points using mean square error (MSE) criterion and is used to replace the finite element model to participate in optimization. Cuckoo algorithm is used to obtain the updating parameters, where the objective function with the minimum frequency response deviation is constructed. And the proposed method is applied to a plane truss model FEMU, and the results are compared with those by the second-order response surface model (RSM) and the radial basis function model (RBF). The analysis results showed that the proposed method has good accuracy and high computational efficiency; errors of updating parameters are less than 0.2%; damage identification is with high precision. After updating, the curves of real and imaginary parts of acceleration FRF are in good agreement with the real ones.

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-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.

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