Wyniki wyszukiwania - BazTech

1

Nonparametric identification of added masses in frequency domain: a numerical study

Suwała G., Biczyk J., Jankowski Ł.

IPPT Reports on Fundamental Technological Research

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2013

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nr 4

37--41

EN

This paper presents a theoretical derivation and reports on a numerical verification of a model-free method for identification of added masses in truss structures. No parametric numerical model of the monitored structure is required, so there is no need for initial model updating and fine tuning. This is a continuation and an improvement of a previous research that resulted in a time-domain identification method, which was tested to be accurate but very time-consuming. A general methodology is briefly introduced, including the inverse problem, and a numerical verification is reported. The aim of the numerical study is to test the accuracy of the proposed method and its sensitivity to various parameters (such as simulated measurement noise and decay rate of the exponential FFT window) in a numerically controlled environment. The verification uses a finite element model of the same real structure that was tested with the time-domain version of the approach. A natural further step is a lab verification based on experimental data.

2

Remodelling of vibrating systems via frequency-domain-based virtual distortion method

Mróz M., Holnicki-Szulc J.

Mechanics / AGH University of Science and Technology

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2005

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Vol. 24, no. 2

124-129

EN

The paper deals with Virtual Distortion Method (VDM) in frequency domain. VDM method is addressed to problems, where steady state response can be the base of the dynamical analysis. The VDM methodology allows fast modification of the original structures without need of modifications of their stiffness, damping and mass matrices. The present work contains the methodology of the new approach, some numerical results of computations and optimization problem. Finally the analysis of sensibility is formulated.

PL

Niniejszy artykuł zajmuje się Metodą Dystorsji Wirtualnych (MDW) w dziedzinie częstotliwości. MDW odnosi się do problemów dynamicznych, w których odpowiedź jest ustalona w czasie. MDW pozwala na szybką modyfikację konstrukcji bez konieczności modyfikacji całej macierzy sztywności, tłumienia czy masy. Praca zawiera sformułowanie nowego podejścia, wyniki obliczeń numerycznych, a także sformułowanie problemu optymalizacji i wrażliwości konstrukcji dla nowego podejścia.

3

Damage identification by the static virtual distortion method

Kołakowski P.

Engineering Transactions

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2004

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Vol. 52, iss.4

253-270

EN

This paper describes the application of a structural reanalysis technique called the Virtual Distortion Method, coupled with an optimisation technique called the Gradient Projection Method, to the damage identification problem for the case of the static structural analysis. The outline of the Virtual Distortion Method is provided and the fundamentals of the Gradient Projection Method are explained. Subsequently the damage identification problem for the static load case is posed. Numerical example of a truss structure is demonstrated. Conclusions are presented with the emphasis on advantages of the employed methods in numerical computations.