Loss tangent (internal friction) for high relaxation strengths and a lognormal distribution of relaxation and retardation times

The loss tangent (internal friction) is evaluated numerically for a lognormal distribution of retardation or relaxation times and high relaxation strengths. It is shown that the loss tangent peak becomes more asymmetrical and the peak width, at half-maximum, decreases as the relaxation strength incr...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Povolo, Francisco, Matteó, Claudia Leda
Publicado: 1991
Materias:
Energy distribution and transfer
relaxation
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03926737_v13_n10_p1267_Povolo
http://hdl.handle.net/20.500.12110/paper_03926737_v13_n10_p1267_Povolo
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_03926737_v13_n10_p1267_Povolo
record_format dspace
spelling paper:paper_03926737_v13_n10_p1267_Povolo2023-06-08T15:40:56Z Loss tangent (internal friction) for high relaxation strengths and a lognormal distribution of relaxation and retardation times Povolo, Francisco Matteó, Claudia Leda Energy distribution and transfer relaxation The loss tangent (internal friction) is evaluated numerically for a lognormal distribution of retardation or relaxation times and high relaxation strengths. It is shown that the loss tangent peak becomes more asymmetrical and the peak width, at half-maximum, decreases as the relaxation strength increases, dropping down to values corresponding to a Debye peak at very large relaxation strengths. Furthermore, the asymmetry of the peak can be used to establish if the lognormal distribution is in the retardation or in the relaxation spectrum. Finally, a procedure which can be used to obtain the relaxation strength, the geometrical parameter of the distribution and the average retardation or relaxation time, from the experimental loss tangent vs. frequency curves, is described. This procedure is applied to actual experimental data reported in the literature for polystyrene. © 1991 Società Italiana di Fisica. Fil:Povolo, F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Matteo, C.L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1991 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03926737_v13_n10_p1267_Povolo http://hdl.handle.net/20.500.12110/paper_03926737_v13_n10_p1267_Povolo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Energy distribution and transfer
relaxation
spellingShingle Energy distribution and transfer
relaxation
Povolo, Francisco
Matteó, Claudia Leda
Loss tangent (internal friction) for high relaxation strengths and a lognormal distribution of relaxation and retardation times
topic_facet Energy distribution and transfer
relaxation
description The loss tangent (internal friction) is evaluated numerically for a lognormal distribution of retardation or relaxation times and high relaxation strengths. It is shown that the loss tangent peak becomes more asymmetrical and the peak width, at half-maximum, decreases as the relaxation strength increases, dropping down to values corresponding to a Debye peak at very large relaxation strengths. Furthermore, the asymmetry of the peak can be used to establish if the lognormal distribution is in the retardation or in the relaxation spectrum. Finally, a procedure which can be used to obtain the relaxation strength, the geometrical parameter of the distribution and the average retardation or relaxation time, from the experimental loss tangent vs. frequency curves, is described. This procedure is applied to actual experimental data reported in the literature for polystyrene. © 1991 Società Italiana di Fisica.
author Povolo, Francisco
Matteó, Claudia Leda
author_facet Povolo, Francisco
Matteó, Claudia Leda
author_sort Povolo, Francisco
title Loss tangent (internal friction) for high relaxation strengths and a lognormal distribution of relaxation and retardation times
title_short Loss tangent (internal friction) for high relaxation strengths and a lognormal distribution of relaxation and retardation times
title_full Loss tangent (internal friction) for high relaxation strengths and a lognormal distribution of relaxation and retardation times
title_fullStr Loss tangent (internal friction) for high relaxation strengths and a lognormal distribution of relaxation and retardation times
title_full_unstemmed Loss tangent (internal friction) for high relaxation strengths and a lognormal distribution of relaxation and retardation times
title_sort loss tangent (internal friction) for high relaxation strengths and a lognormal distribution of relaxation and retardation times
publishDate 1991
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03926737_v13_n10_p1267_Povolo
http://hdl.handle.net/20.500.12110/paper_03926737_v13_n10_p1267_Povolo
work_keys_str_mv AT povolofrancisco losstangentinternalfrictionforhighrelaxationstrengthsandalognormaldistributionofrelaxationandretardationtimes
AT matteoclaudialeda losstangentinternalfrictionforhighrelaxationstrengthsandalognormaldistributionofrelaxationandretardationtimes
_version_ 1768544089177849856

Ejemplares similares