Author
Jean Piranda
Bio: Jean Piranda is an academic researcher from University of Franche-Comté. The author has contributed to research in topics: Modal analysis & System identification. The author has an hindex of 4, co-authored 8 publications receiving 99 citations.
Papers
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TL;DR: In this article, the stiffness properties of composite materials from dynamic tests are identified by a technique of model updating, which is based on the minimization of the eigensolution residuals (sensitivity method).
Abstract: This work consists of the identification of the stiffness properties of composite materials from dynamic tests. Unknown coefficients are identified by a technique of model updating. The formulation used (modal approach) is based on the minimization of the eigensolution residuals (sensitivity method). This technique allows the simultaneous identification of several properties from a single test. Stiffness properties of extension, bending, twisting and transverse shear have been identified. A discussion of the different identification approaches of elastic constants of composite materials from dynamic tests has been presented. Important points of the model updating in dynamics have been addressed: generalized mass errors, placement of sensors and approximate reanalysis of eigensolutions. Results obtained by numerical simulations show the efficiency of the proposed methodology.
36 citations
TL;DR: In this article, the authors focused on the nonlinear damping capacity of built-up structures owing to presence of frictional joints and introduced a novel experimental procedure based on the wavelet transform providing equivalent modal parameters identification.
33 citations
TL;DR: In this paper, the authors proposed a non-centralized IFF control strategy to increase the implementation efficiency of a plate-based control system, not only in terms of induced damping and signal magnitudes, but also in the sense that the best designed system can be coupled with a noncentralized approach.
Abstract: Collocated IFF control strategy is commonly used thanks to its strong quality of robustness, which is due to its intrinsic damping property. Up to now, the extensive studies available in the literature have focused only on the obtained mechanical efficiency in terms of modal damping ratios. We propose here to exhibit some mechanical design parameters allowing one to really optimize this dissipation strategy, not only in terms of induced damping, but also in terms of control signal magnitudes. We apply our criterion to two different plate systems to emphasize the effects of such design variables on the control implementation. At the end, we demonstrate how the best designed system can be coupled with a non-centralized approach to increase the implementation efficiency. Copyright © 2004 John Wiley & Sons, Ltd.
22 citations
01 Jan 2001
TL;DR: In this paper, the authors present some of the techniques developed to solve the following questions: how can we know where the nodes of the FEM are located in the picture? What is the sensitivity direction and how to take it into account? How can we obtain a reliable measurement of the amplitude and phase of the displacement with respect to the driving force?
Abstract: Electronic Speckle Pattern Interferometry (ESPI) is a recent optical way to measure a vibrating structure under sine excitation. The spatial density of the obtained information is about 10000 times larger than with the classical accelerometric technique, leading to the possibility of knowing the displacement at each node of the Finite Element Model (FEM). We present here some of the techniques we developed to solve the following questions: how can we know where the nodes of the FEM are located in the picture ? What is the sensitivity direction and how to take it into account ? How can we obtain a reliable measurement of the amplitude and phase of the displacement with respect to the driving force ? Each of these points needs to be treated before using the optical data in a FEM updating procedure.
6 citations
TL;DR: In this paper, two methodes experimentales ont been used to evaluate the parametres modaux d a structure assemblee, in order to identify the effect of different modes of vibration on the performance of the structure.
Abstract: Les structures complexes sont generalement construites a partir d'elements simples assembles par differentes techniques : rivetage, boulonnage, soudure par points ... La perte d'energie constatee au niveau des liaisons est beaucoup plus importante que celle intrinseque au materiau. Elle conditionne par consequent l'amortissement des modes propres de vibration. Cet amortissement dependant de la pression au niveau du contact entre surfaces est generalement une fonction non-lineaire de l'amplitude des vibrations puisqu'il depend d'un phenomene complexe de stick/slip a l'interface entre composants. L'analyse experimentale presentee ici a pour objectif l'evaluation des parametres modaux d'une structure assemblee. Deux methodes experimentales ont ete mises en œuvre pour identifier l'amortissement modal des cinq premiers modes propres en fonction de l'amplitude des vibrations. Dans un premier temps, l'amortissement a ete identifie par lissage de fonction de transfert. Nous avons ensuite applique la methode de decrement logarithmique dans le plan temps-frequence en utilisant la transformee en ondelettes. Enfin, des mesures interferometriques ont ete effectuees afin d'observer l'influence de la jonction sur les deformees modales. Ces resultats ont permis d'identifier les effets de l'assemblage autant de facon qualitative que quantitative.
3 citations
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TL;DR: In this paper, the authors present a survey of the key developments which arose in the field since 2006, and illustrate state-of-the-art techniques using a real-world satellite structure.
353 citations
TL;DR: This paper deals with the direct and simultaneous estimation of parameters used in some constitutive laws by a specific procedure based on a relevant use of the principle of virtual work to provide directly the unknown parameters.
160 citations
TL;DR: In this article, the authors present a review of structural dynamic model updating techniques, starting with a tutorial introduction of basic concepts of model updating, the paper reviews direct and iterative techniques of update along with their applications to real life systems.
Abstract: This paper presents a review of structural dynamic model updating techniques. Starting with a tutorial introduction of basic concepts of model updating, the paper reviews direct and iterative techniques of model updating along with their applications to real life systems. The main objective of this paper is to review the most widely applied model updating techniques so that beginners as well as practising engineers can appreciate, choose and then utilize the most suitable model updating technique for their customized application. Another objective is to highlight the current issues, applications and observations for further advancements in the field of model updating.
129 citations
TL;DR: In this article, the authors deal with the direct identification of mechanical parameters that govern the in-plane constitutive law of orthotropic materials, which are extracted from heterogeneous strain fields that occur in a short beam specimen tested in a Iosipescu fixture.
105 citations
TL;DR: In this article, an adaptive harmonic balance method is proposed based on the relative variation of an approximate strain energy for two consecutive numbers of harmonics, which is also expressed in a condensation case.
77 citations