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Damage identification of a 3D full scale steel-concrete composite structure with partial-strength joints at different pseudo-dynamic load levels / M. Molinari in Earthquake engineering structural dynamics, Vol. 38 N° 10 (Août 2009) 

Public ISBD [article]  in Earthquake engineering structural dynamics > Vol. 38 N° 10 (Août 2009) . - pp. 1219-1236 Titre : Damage identification of a 3D full scale steel-concrete composite structure with partial-strength joints at different pseudo-dynamic load levels Type de document : texte imprimé Auteurs : M. Molinari, Auteur ; A. T. Savadkoohi, Auteur ; O. S. Bursi, Auteur Article en page(s) : pp. 1219-1236 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Damage  assessment;  Pseudo-dynamic  tests;  Model  updating  ;  Sensitivity  analysis Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Partial-strength composite steel-concrete moment-resisting (MR) frame structures represent an open research field in seismic design from both a theoretical and an experimental standpoint. Among experimental techniques, vibration testing is a well-known and powerful technique for damage detection, localization and quantification, where actual modal parameters of a structure at different states can be determined from test data by using system identification methods. However, the identification of semi-rigid connections in framed structures is limited, and hence this paper focuses on a series of vibration experiments that were carried out on a realistic MR frame structure, following the application of pseudo-dynamic and quasi-static cyclic loadings at the European laboratory for structural assessment of the Joint Research Centre at Ispra, Italy, with the scope of understanding the structural behaviour and identifying changes in the dynamic response. From the forced vibration response, natural frequencies, damping ratios, modal displacements and rotations were extracted using the circle fitting technique. These modal parameters were used for local and global damage identification by updating a 3D finite element model of the intact structure. The identified results were then correlated with observations performed on the structure to understand further the underlying damage mechanisms. Finally, the latin hypercube sampling technique, a variant of the Monte Carlo method, was employed in order to study the sensitivity of the updated parameters of the 3D model to noise on the modal inputs. ISSN : 0098-8847 En ligne : www.interscience.wiley.com/journal/eqe [article] Damage identification of a 3D full scale steel-concrete composite structure with partial-strength joints at different pseudo-dynamic load levels [texte imprimé] / M. Molinari, Auteur ; A. T. Savadkoohi, Auteur ; O. S. Bursi, Auteur . - pp. 1219-1236. Génie Civil Langues : Anglais (eng) in Earthquake engineering structural dynamics > Vol. 38 N° 10 (Août 2009) . - pp. 1219-1236 Mots-clés : Damage  assessment;  Pseudo-dynamic  tests;  Model  updating  ;  Sensitivity  analysis Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Partial-strength composite steel-concrete moment-resisting (MR) frame structures represent an open research field in seismic design from both a theoretical and an experimental standpoint. Among experimental techniques, vibration testing is a well-known and powerful technique for damage detection, localization and quantification, where actual modal parameters of a structure at different states can be determined from test data by using system identification methods. However, the identification of semi-rigid connections in framed structures is limited, and hence this paper focuses on a series of vibration experiments that were carried out on a realistic MR frame structure, following the application of pseudo-dynamic and quasi-static cyclic loadings at the European laboratory for structural assessment of the Joint Research Centre at Ispra, Italy, with the scope of understanding the structural behaviour and identifying changes in the dynamic response. From the forced vibration response, natural frequencies, damping ratios, modal displacements and rotations were extracted using the circle fitting technique. These modal parameters were used for local and global damage identification by updating a 3D finite element model of the intact structure. The identified results were then correlated with observations performed on the structure to understand further the underlying damage mechanisms. Finally, the latin hypercube sampling technique, a variant of the Monte Carlo method, was employed in order to study the sensitivity of the updated parameters of the 3D model to noise on the modal inputs. ISSN : 0098-8847 En ligne : www.interscience.wiley.com/journal/eqe

A Rosenbrock-W method for real-time dynamic substructuring and pseudo-dynamic testing / C. P. Lamarche in Earthquake engineering structural dynamics, Vol. 38 N° 9 (Juillet 2009) 

Public ISBD [article]  in Earthquake engineering structural dynamics > Vol. 38 N° 9 (Juillet 2009) . - pp. 1071-1092 Titre : A Rosenbrock-W method for real-time dynamic substructuring and pseudo-dynamic testing Type de document : texte imprimé Auteurs : C. P. Lamarche, Auteur ; A. Bonelli, Auteur ; O. S. Bursi, Auteur Article en page(s) : pp. 1071-1092 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Substructuring;  Hybrid  testing;  Stability;  Convergence  ;  Real-time  testing;  Jacobian Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A variant of the Rosenbrock-W integration method is proposed for real-time dynamic substructuring and pseudo-dynamic testing. In this variant, an approximation of the Jacobian matrix that accounts for the properties of both the physical and numerical substructures is used throughout the analysis process. Only an initial estimate of the stiffness and damping properties of the physical components is required. It is demonstrated that the method is unconditionally stable provided that specific conditions are fulfilled and that the order accuracy can be maintained in the nonlinear regime without involving any matrix inversion while testing. The method also features controllable numerical energy dissipation characteristics and explicit expression of the target displacement and velocity vectors. The stability and accuracy of the proposed integration scheme are examined in the paper. The method has also been verified through hybrid testing performed of SDOF and MDOF structures with linear and highly nonlinear physical substructures. The results are compared with those obtained from the operator splitting method. An approach based on the modal decomposition principle is presented to predict the potential effect of experimental errors on the overall response during testing. ISSN : 0098-8847 En ligne : http://www3.interscience.wiley.com/journal/121632331/abstract [article] A Rosenbrock-W method for real-time dynamic substructuring and pseudo-dynamic testing [texte imprimé] / C. P. Lamarche, Auteur ; A. Bonelli, Auteur ; O. S. Bursi, Auteur . - pp. 1071-1092. Génie Civil Langues : Anglais (eng) in Earthquake engineering structural dynamics > Vol. 38 N° 9 (Juillet 2009) . - pp. 1071-1092 Mots-clés : Substructuring;  Hybrid  testing;  Stability;  Convergence  ;  Real-time  testing;  Jacobian Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A variant of the Rosenbrock-W integration method is proposed for real-time dynamic substructuring and pseudo-dynamic testing. In this variant, an approximation of the Jacobian matrix that accounts for the properties of both the physical and numerical substructures is used throughout the analysis process. Only an initial estimate of the stiffness and damping properties of the physical components is required. It is demonstrated that the method is unconditionally stable provided that specific conditions are fulfilled and that the order accuracy can be maintained in the nonlinear regime without involving any matrix inversion while testing. The method also features controllable numerical energy dissipation characteristics and explicit expression of the target displacement and velocity vectors. The stability and accuracy of the proposed integration scheme are examined in the paper. The method has also been verified through hybrid testing performed of SDOF and MDOF structures with linear and highly nonlinear physical substructures. The results are compared with those obtained from the operator splitting method. An approach based on the modal decomposition principle is presented to predict the potential effect of experimental errors on the overall response during testing. ISSN : 0098-8847 En ligne : http://www3.interscience.wiley.com/journal/121632331/abstract