scholarly journals Dynamic Model Updating Using Virtual Antiresonances

2004 ◽  
Vol 11 (3-4) ◽  
pp. 351-363 ◽  
Author(s):  
Walter D’Ambrogio ◽  
Annalisa Fregolent
Keyword(s):  
Finite Element ◽  
High Frequency ◽  
Model Updating ◽  
Element Model ◽  
Mode Shapes ◽  
Finite Element Model Updating ◽  
Frequency Error ◽  
Modal Expansion ◽  
Modal Data ◽  
The Finite Element Model

This paper considers an extension of the model updating method that minimizes the antiresonance error, besides the natural frequency error. By defining virtual antiresonances, this extension allows the use of previously identified modal data. Virtual antiresonances can be evaluated from a truncated modal expansion, and do not correspond to any physical system. The method is applied to the Finite Element model updating of the GARTEUR benchmark, used within an European project on updating. Results are compared with those previously obtained by estimating actual antiresonances after computing low and high frequency residuals, and with results obtained by using the correlation (MAC) between identified and analytical mode shapes.

Dynamic Characteristics and Finite Element Model Updating of Micromachined Torsion Structures

2013 ◽  
Vol 284-287 ◽  
pp. 1831-1835
Author(s):  
Wei Hsin Gau ◽  
Kun Nan Chen ◽  
Yunn Lin Hwang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Speckle Pattern ◽  
Element Model ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Finite Element Model Updating ◽  
Element Analysis

In this paper, two experimental techniques, Electronic Speckle Pattern Interferometry and Stroboscopic Interferometry, and two different finite element analysis packages are used to measure or to analyze the frequencies and mode shapes of a micromachined, cross-shaped torsion structure. Four sets of modal data are compared and shown having a significant discrepancy in their frequency values, although their mode shapes are quite consistent. Inconsistency in the frequency results due to erroneous inputs of geometrical and material parameters to the finite element analysis can be salvaged by applying the finite element model updating procedure. Two updating cases show that the optimization sequences converge quickly and significant improvements in frequency prediction are achieved. With the inclusion of the thickness parameter, the second case yields a maximum of under 0.4% in frequency difference, and all parameters attain more reliable updated values.

The Study of Spacecraft Finite Element Model Updating System

2011 ◽  
Vol 121-126 ◽  
pp. 4852-4857
Author(s):  
Xun Tao Liu ◽  
Zhao Bo Chen ◽  
Shan Yun Huang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Element Model ◽  
Finite Element Model Updating ◽  
Frequency Error ◽  
Analysis Tool ◽  
Design Quality ◽  
Vibration Direction ◽  
Finite Element Technology

with the development of finite element technology, finite element model is becoming to the main analysis tool. However, because some theoretic assumptions, unsuitable constraint and uncertain material property are applied, the simulation result of finite element model isn’t different from the testing data. In order to improve the design quality and safety of spacecraft, this paper deduced the formula of spacecraft finite element updating, developed the spacecraft finite element model updating system, the software mainly of five parts: the frequency response function calculation, the loading inverse solution, the finite element model updating, the data display, virtual experimentation. Software can complete exciting force inverse, parameter sensitivity analysis, parameters screening and finite element model updating. The calculation result of updated finite element model is in accordance with testing curve shape on the main vibration direction, first-order frequency error is ±5%, response error is ±10%. Software meet the need of finite element model updating, it provide a software base for spacecraft design.

Finite Element Model Updating for Unsymmetrical Damping System with Genetic Algorithm

2012 ◽  
Vol 166-169 ◽  
pp. 2999-3003 ◽  
Author(s):  
Bao Qiang Zhang ◽  
Guo Ping Chen ◽  
Qin Tao Guo
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Element Model ◽  
Maximum Error ◽  
Optimization Method ◽  
Finite Element Model Updating ◽  
Modal Data ◽  
Complex Modal

Finite element model updating using incomplete complex modal data for unsymmetrical damping system with genetic algorithm is presented. The genetic algorithm method and finite element model updating based on optimization method using complex modal eigenvalue are introduced. The updating for simulation example about a flexible rotor system which is a typical unsymmetrical damping system is performed using bearing stiffness, bearing damping and diameter moment of inertia parameters. The results show that the maximum error of updated parameters is 0.15% and the objective function of genetic algorithm is 0.0081. The study demonstrates that the finite element model updating method using incomplete complex modal data with genetic algorithm is feasible and effective for unsymmetrical damping system.

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