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Mechanical model parameters for viscoelastic dampers / Chang, T.-S. in Journal of engineering mechanics, Vol. 135 N° 6 (Juin 2009) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 135 N° 6 (Juin 2009) . - pp. 581-584 Titre : Mechanical model parameters for viscoelastic dampers Type de document : texte imprimé Auteurs : Chang, T.-S., Auteur ; M. P. Singh, Auteur Article en page(s) : pp. 581-584 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Mechanical  properties  Parameters  Viscoelasticity  Damping. Résumé : Models of varying complexities are being used to represent the frequency-dependent dynamic force deformation characteristics of viscoelastic dampers. More sophisticated models with real or complex fractional derivatives can definitely capture the frequency-dependent properties better. However, since these advanced models add complexity in the analysis of structures, the use of two classical models—a Kelvin chain and a Maxwell ladder—consisting of usual dashpots and springs is suggested. In this technical note, we provide explicit steps and necessary formulas to calculate the parameters of these two proposed models to provide desired frequency-dependent characteristics represented by the storage and loss moduli. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...] [article] Mechanical model parameters for viscoelastic dampers [texte imprimé] / Chang, T.-S., Auteur ; M. P. Singh, Auteur . - pp. 581-584. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 135 N° 6 (Juin 2009) . - pp. 581-584 Mots-clés : Mechanical  properties  Parameters  Viscoelasticity  Damping. Résumé : Models of varying complexities are being used to represent the frequency-dependent dynamic force deformation characteristics of viscoelastic dampers. More sophisticated models with real or complex fractional derivatives can definitely capture the frequency-dependent properties better. However, since these advanced models add complexity in the analysis of structures, the use of two classical models—a Kelvin chain and a Maxwell ladder—consisting of usual dashpots and springs is suggested. In this technical note, we provide explicit steps and necessary formulas to calculate the parameters of these two proposed models to provide desired frequency-dependent characteristics represented by the storage and loss moduli. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...]

Seismic analysis of structures with viscoelastic dampers / M. P. Singh in Journal of engineering mechanics, Vol. 135 N° 6 (Juin 2009) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 135 N° 6 (Juin 2009) . - pp. 571-580 Titre : Seismic analysis of structures with viscoelastic dampers Type de document : texte imprimé Auteurs : M. P. Singh, Auteur ; Chang, T.-S., Auteur Article en page(s) : pp. 571-580 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Seismic  analysis  Viscoelasticity  Damping  Structural  control. Résumé : Viscoelastic dampers are being used in structures to mitigate dynamic effects. The models of varying complexities from simple maxwell element to differential models with fractional and complex order derivatives have been used to represent their frequency-dependent force deformation characteristics. More complex models are able to capture the frequency dependence of the material properties better, but are difficult to use in analyses. However, the classical models consisting of assemblies of Kelvin and/or Maxwell elements with an adequate number of parameters can be formed to capture the frequency dependence as accurately as the more sophisticated fractional derivative models can do. The main advantage in adopting these classical models is a simpler and smaller system of equations, which can be conveniently analyzed for nonlinear and linear systems. In this study, the two classical mechanical models consisting of Kelvin chains and Maxwell ladder are used. It is shown that these mechanical models are as effective as the fractional derivative model in capturing the effect of the frequency dependence of the material properties in response calculations and are more convenient to use in dynamic response analyses. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...] [article] Seismic analysis of structures with viscoelastic dampers [texte imprimé] / M. P. Singh, Auteur ; Chang, T.-S., Auteur . - pp. 571-580. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 135 N° 6 (Juin 2009) . - pp. 571-580 Mots-clés : Seismic  analysis  Viscoelasticity  Damping  Structural  control. Résumé : Viscoelastic dampers are being used in structures to mitigate dynamic effects. The models of varying complexities from simple maxwell element to differential models with fractional and complex order derivatives have been used to represent their frequency-dependent force deformation characteristics. More complex models are able to capture the frequency dependence of the material properties better, but are difficult to use in analyses. However, the classical models consisting of assemblies of Kelvin and/or Maxwell elements with an adequate number of parameters can be formed to capture the frequency dependence as accurately as the more sophisticated fractional derivative models can do. The main advantage in adopting these classical models is a simpler and smaller system of equations, which can be conveniently analyzed for nonlinear and linear systems. In this study, the two classical mechanical models consisting of Kelvin chains and Maxwell ladder are used. It is shown that these mechanical models are as effective as the fractional derivative model in capturing the effect of the frequency dependence of the material properties in response calculations and are more convenient to use in dynamic response analyses. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...]