Documents disponibles écrits par cet auteur

Fragility analysis and seismic record selection / G. P. Cimellaro in Journal of structural engineering, Vol. 137 N° 3 (Mars 2011) 

Public ISBD [article]  in Journal of structural engineering > Vol. 137 N° 3 (Mars 2011) . - pp. 379-390 Titre : Fragility analysis and seismic record selection Type de document : texte imprimé Auteurs : G. P. Cimellaro, Auteur ; Reinhorn, A. M., Auteur ; A. D’Ambrisi, Auteur Année de publication : 2011 Article en page(s) : pp. 379-390 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Damage  Fragility  functions  Intensity  measure  Nonlinear  analysis  Record  selection  Uniform  hazard  spectrum  Spectrum  matching  Stationary  simulation  Synthetic  earthquakes  Acceleration  scaling  Accelerograms  matching  Inelastic  demand Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper explores the influence of spectrum-matched and amplitude-scaled ground motions on the development of fragility functions for structures. The quantification of the influence of these two types of ensembles on ground motions in predicting demands of structural and nonstructural systems is addressed. Moreover, the paper investigates the sensitivity of number of accelerograms in the ensembles, which produces consistent results in the nonlinear analyses. A multidegree-of-freedom (MDOF) inelastic shear-type building is used in the evaluations. The median and the dispersion of different types of damage measures are evaluated at each story and the effect of different levels of nonlinearity is investigated. Fragility functions are developed for structural and nonstructural components using the maximum likelihood method from the response generated with the selected ground motions. The sufficient number of ground motions necessary in the estimation of the response parameters and on the evaluation of the fragility functions is presented herein. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i3/p379_s1?isAuthorized=no [article] Fragility analysis and seismic record selection [texte imprimé] / G. P. Cimellaro, Auteur ; Reinhorn, A. M., Auteur ; A. D’Ambrisi, Auteur . - 2011 . - pp. 379-390. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 137 N° 3 (Mars 2011) . - pp. 379-390 Mots-clés : Damage  Fragility  functions  Intensity  measure  Nonlinear  analysis  Record  selection  Uniform  hazard  spectrum  Spectrum  matching  Stationary  simulation  Synthetic  earthquakes  Acceleration  scaling  Accelerograms  matching  Inelastic  demand Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper explores the influence of spectrum-matched and amplitude-scaled ground motions on the development of fragility functions for structures. The quantification of the influence of these two types of ensembles on ground motions in predicting demands of structural and nonstructural systems is addressed. Moreover, the paper investigates the sensitivity of number of accelerograms in the ensembles, which produces consistent results in the nonlinear analyses. A multidegree-of-freedom (MDOF) inelastic shear-type building is used in the evaluations. The median and the dispersion of different types of damage measures are evaluated at each story and the effect of different levels of nonlinearity is investigated. Fragility functions are developed for structural and nonstructural components using the maximum likelihood method from the response generated with the selected ground motions. The sufficient number of ground motions necessary in the estimation of the response parameters and on the evaluation of the fragility functions is presented herein. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i3/p379_s1?isAuthorized=no

Multidimensional performance limit state for hazard fragility functions / G. P. Cimellaro in Journal of engineering mechanics, Vol. 137 N° 1 (Janvier 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 137 N° 1 (Janvier 2011) . - pp.47-60 Titre : Multidimensional performance limit state for hazard fragility functions Type de document : texte imprimé Auteurs : G. P. Cimellaro, Auteur ; A. M. Reinhorn, Auteur Année de publication : 2011 Article en page(s) : pp.47-60 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Hazards  Limit  states  Structural  reliability  Rehabilitation  Safety  California  Health  care  facilities. Résumé : This paper addresses an alternative methodology to calculate fragility functions that considers multiple limit states parameters, such as combinations of response variables of accelerations and interstory drifts. Limit states are defined using a generalized multidimensional limit states function that allows considering dependencies among limit thresholds modeled as random variables in the calculation of fragility curves that are evaluated as function of the return period. A California hospital is used as example to illustrate the proposed approach for developing fragility curves. The study investigates the sensitivity of the proposed approach for evaluating fragility curves when uncertainties in limit states are considered. Influence of structural and response parameters, such as stiffness, damping, acceleration and displacement thresholds, ground motion input, and uncertainties in structural modeling, are also investigated. The proposed approach can be considered as an alternative approach for describing the vulnerable behavior of nonstructural components that are sensitive to multiple parameters such as displacements and accelerations (e.g., partition walls, piping systems, etc.). DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i1/p47_s1?isAuthorized=no [article] Multidimensional performance limit state for hazard fragility functions [texte imprimé] / G. P. Cimellaro, Auteur ; A. M. Reinhorn, Auteur . - 2011 . - pp.47-60. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 137 N° 1 (Janvier 2011) . - pp.47-60 Mots-clés : Hazards  Limit  states  Structural  reliability  Rehabilitation  Safety  California  Health  care  facilities. Résumé : This paper addresses an alternative methodology to calculate fragility functions that considers multiple limit states parameters, such as combinations of response variables of accelerations and interstory drifts. Limit states are defined using a generalized multidimensional limit states function that allows considering dependencies among limit thresholds modeled as random variables in the calculation of fragility curves that are evaluated as function of the return period. A California hospital is used as example to illustrate the proposed approach for developing fragility curves. The study investigates the sensitivity of the proposed approach for evaluating fragility curves when uncertainties in limit states are considered. Influence of structural and response parameters, such as stiffness, damping, acceleration and displacement thresholds, ground motion input, and uncertainties in structural modeling, are also investigated. The proposed approach can be considered as an alternative approach for describing the vulnerable behavior of nonstructural components that are sensitive to multiple parameters such as displacements and accelerations (e.g., partition walls, piping systems, etc.). DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i1/p47_s1?isAuthorized=no

Output-only modal identification of ancient l’Aquila city hall and civic tower / G. P. Cimellaro in Journal of structural engineering, Vol. 138 N° 4 (Avril 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 481–491 Titre : Output-only modal identification of ancient l’Aquila city hall and civic tower Type de document : texte imprimé Auteurs : G. P. Cimellaro, Auteur ; S. Piantà, Auteur ; A. De Stefano, Auteur Année de publication : 2012 Article en page(s) : pp. 481–491 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Output-only  modal  identification  Frequency  domain  decomposition  (FDD)  Eigensystem  realization  algorithm  (ERA)  Random  decrement  (RD)  Masonry  structure  Finite-element  model  Ambient  vibration  Identification  EMA  Operational  modal  analysis Résumé : The ancient masonry city hall in L’Aquila, Italy (Margherita Palace) that was severely damaged during the L’Aquila earthquake in April 2009 has been subjected to ambient vibration tests to determine its dynamic characteristics such as the natural frequencies, mode shapes, and damping ratios. The processing of ambient vibration responses is performed with three output-only identification approaches: (1) the frequency-domain decomposition, (2) random decrement (RD) technique combined with the eigensystem realization algorithm (ERA), and (3) the natural excitation technique (NExT) combined with ERA. Measurements were made in the palace and in the civic tower using 15 sensors in three different configurations, and the ambient vibration tests involved the simultaneous measurements of longitudinal and lateral vibrations. Lateral vibration modes for the civic tower were identified clearly; a total of five modal shapes and frequencies were identified in the frequency range 0 to 7 Hz. The modal identification in the palace was more difficult because of the severe damage; however, the two bending modes in the perpendicular directions were identified. The comparison of the three experimental techniques shows good agreement, confirming the reliability of the three identification methods. The results of the modal identification have been used to update the finite-element model of the palace. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000494 [article] Output-only modal identification of ancient l’Aquila city hall and civic tower [texte imprimé] / G. P. Cimellaro, Auteur ; S. Piantà, Auteur ; A. De Stefano, Auteur . - 2012 . - pp. 481–491. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 481–491 Mots-clés : Output-only  modal  identification  Frequency  domain  decomposition  (FDD)  Eigensystem  realization  algorithm  (ERA)  Random  decrement  (RD)  Masonry  structure  Finite-element  model  Ambient  vibration  Identification  EMA  Operational  modal  analysis Résumé : The ancient masonry city hall in L’Aquila, Italy (Margherita Palace) that was severely damaged during the L’Aquila earthquake in April 2009 has been subjected to ambient vibration tests to determine its dynamic characteristics such as the natural frequencies, mode shapes, and damping ratios. The processing of ambient vibration responses is performed with three output-only identification approaches: (1) the frequency-domain decomposition, (2) random decrement (RD) technique combined with the eigensystem realization algorithm (ERA), and (3) the natural excitation technique (NExT) combined with ERA. Measurements were made in the palace and in the civic tower using 15 sensors in three different configurations, and the ambient vibration tests involved the simultaneous measurements of longitudinal and lateral vibrations. Lateral vibration modes for the civic tower were identified clearly; a total of five modal shapes and frequencies were identified in the frequency range 0 to 7 Hz. The modal identification in the palace was more difficult because of the severe damage; however, the two bending modes in the perpendicular directions were identified. The comparison of the three experimental techniques shows good agreement, confirming the reliability of the three identification methods. The results of the modal identification have been used to update the finite-element model of the palace. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000494