  Qualification d’un appareil d'éclairage décoratif soumis aux vibrations induites par un pont ferroviaire; ; Golinval, Jean-Claude  Scientific conference (2012, November) Au même titre que la plupart des pièces mécaniques soumises aux vibrations, les appareils d'éclairage installés en extérieur sont amenés à satisfaire, en fonction de leurs conditions d’utilisation, aux ... [more ▼] Au même titre que la plupart des pièces mécaniques soumises aux vibrations, les appareils d'éclairage installés en extérieur sont amenés à satisfaire, en fonction de leurs conditions d’utilisation, aux exigences de procédures d'essais appliquées sur table vibrante. Celles-ci ont pour but de garantir l'intégrité structurelle du luminaire lorsque, une fois sur site, il est soumis aux effets du vent. Dans le cas des appareils d'éclairage décoratifs installés sur un pont de chemin de fer de structure métallique, le vent n'étant plus la source principale de vibrations en comparaison du trafic ferroviaire, on est dès lors confronté à une absence de toute indication appropriée décrivant l'essai à mener. Par conséquent, l'objectif de cette étude est d'élaborer une spécification d'essai de durée réduite, appliquée en laboratoire sur table vibrante, et représentative de l'environnement vibratoire réel de l'appareil à certifier. Sur base des essais réalisés en laboratoire, des prescriptions de montage et d'installation sont également formulées afin de garantir des conditions d’utilisation et d’essai identiques. [less ▲] Detailed reference viewed: 20 (1 ULg)Qualification Procedure of Luminaires in the Event of an Impact to the Pole; ; Golinval, Jean-Claude Conference given outside the academic context (2009) The objective of the study is to develop a testing specification on an electrodynamic shaker which ensures the qualification of a parking lighting device, whose pole is impacted by a car. The methodology ... [more ▼] The objective of the study is to develop a testing specification on an electrodynamic shaker which ensures the qualification of a parking lighting device, whose pole is impacted by a car. The methodology is based on both a numerical approach and an experimental approach using an electrodynamic shaker. The first step of the analysis consists in modeling the structure and the excitation by means of a finite element approach. The calculation of the dynamic response of the "pole/lighting device" system to impact loading is repeated for different geometries of the pole. The second step is to consider each dynamic response at the fixing point of the lighting device on the pole as input for a base-excited single degree of freedom system. The theory developed for such a system allows to define severity criteria like the Shock Response Spectrum (SRS) which is the most representative criterion in the case of an impact. The severity of the vibration environment of the lighting device is then obtained by considering the envelope of the different computed SRS. Finally, different test specifications leading to equivalent SRS are proposed and the device is tested on an electrodynamic shaker. The developed methodology was applied to the NEMO lighting device (Schréder). [less ▲] Detailed reference viewed: 52 (8 ULg) Optimal design of fixtures for vibration testing of structures on electro-dynamic shakerPoncelet, Fabien ; ; Fleury, Claude et alConference given outside the academic context (2005) The structural design of fixtures for vibration testing of structures on electro-dynamic shakers correspond to a constrained optimization problem. The design methodology proposed in this paper is based on ... [more ▼] The structural design of fixtures for vibration testing of structures on electro-dynamic shakers correspond to a constrained optimization problem. The design methodology proposed in this paper is based on topological optimization tools. It is illustrated on industrial application examples such as the vibration testing of a space mirror and a street lighting device. [less ▲] Detailed reference viewed: 26 (2 ULg)Fault Detection Algorithm based on Null-Space Analysis for On-Line Structural Health Monitoring; Golinval, Jean-Claude ; Conference given outside the academic context (2005) Early diagnosis of structural damages or machinery malfunctions allows to reduce the maintenance cost of systems and to increase their reliability and safety. This paper addresses the damage detection ... [more ▼] Early diagnosis of structural damages or machinery malfunctions allows to reduce the maintenance cost of systems and to increase their reliability and safety. This paper addresses the damage detection problem by statistical analysis on output-only measurements of structures. The developed method is based on subspace analysis of the Hankel matrices constructed by vibration measurement data. The column active subspace of the Hankel matrix defined by the first principal components is orthonormal to the column null-subspace defined by the remaining principal components. The residue in the orthonormality relation obtained from different data sets may be used to detect structural damages. It is illustrated that this null-space-based method constitutes an enhancement of the classical damage detection method based on principal component analysis (PCA). Several damage indicators are proposed to characterize the resulting residue matrices. The method is first illustrated on a numerical example and then, it is applied to vibration fatigue testing of a street-lighting device. Because of its simplicity and efficiency, the proposed algorithm is expected to be suitable for continuous on-line health monitoring of structures in practical situations. [less ▲] Detailed reference viewed: 30 (0 ULg)Null-Subspace Analysis for Structural Damage Monitoring in Fatigue Testing of Luminaires; ; Golinval, Jean-Claude Conference given outside the academic context (2004) A damage detection method of mechanical system based on output measurements only and on the subspace identification concept is presented. The method uses the definition of null subspace analysis of the ... [more ▼] A damage detection method of mechanical system based on output measurements only and on the subspace identification concept is presented. The method uses the definition of null subspace analysis of the Hankel matrix. It is demonstrated to be sensitive to small-size structural damages and suitable for continuous on-line monitoring. The measured response records of structures under environmental or artificial vibrations are assembled in the Hankel matrix that is further factorized into special subspaces. The active subspace defined by the first principal components is shown to be orthonormal to the null subspace defined by the remaining principal components. Therefore, any evident increase of the residues signifies possible structural damages. The method is illustrated by an application to fatigue tests of a street lighting device (luminaires). Experimental methods and numerical calculations on luminaires are simply described and discussed. The test results show that the developed methods may be easily used to effectively monitor the damage evolution during the fatigue tests. [less ▲] Detailed reference viewed: 25 (1 ULg)Comparison of the Severity of Standards Used for the Vibration Testing of Luminaires; Golinval, Jean-Claude ; et alConference given outside the academic context (2003) Detailed reference viewed: 13 (1 ULg)Accelerated Fatigue Testing Methodology of Luminaires on Electro-Dynamic Shaker; Golinval, Jean-Claude ; Conference given outside the academic context (2002) Detailed reference viewed: 20 (1 ULg)Aerodynamic and Mechanical Design of Compressor Blades Including Static Analysis; ; Essers, Jean-André et alin Proceedings od the 3rd World Congress of Structural and Multidisciplinary Optimization (1999, May) Detailed reference viewed: 53 (4 ULg) |
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