Influence of intensity of relaxation on interconversion between normalized distribution functions

Relaxation and retardation spectra comprise both the statistical processes and the macroscopic behavior of a linear viscoelastic material. Effectively, they provide the distribution function of the mechanical processes that evolve in the polymeric system and their integrals give the difference betwe...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Povolo, F., Hermida, ȁ.B.
Formato: JOUR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00323896_v24_n1_p1_Povolo
Aporte de:
id todo:paper_00323896_v24_n1_p1_Povolo
record_format dspace
spelling todo:paper_00323896_v24_n1_p1_Povolo2023-10-03T14:45:15Z Influence of intensity of relaxation on interconversion between normalized distribution functions Povolo, F. Hermida, ȁ.B. Dynamic mechanical properties Linear viscoelasticity Master curve Relaxation and retardation spectra Relaxation Processes - Analysis Spectrum Analysis - Applications Viscoelasticity - Theory Interconversion Linear Viscoelasticity Macroscopic Response Master Curves Relaxation and Retardation Spectra Polymers Relaxation and retardation spectra comprise both the statistical processes and the macroscopic behavior of a linear viscoelastic material. Effectively, they provide the distribution function of the mechanical processes that evolve in the polymeric system and their integrals give the difference between the limiting moduli or compliances. Consequently, the normal procedure used for the interconversion between the spectra does not allow to separate the statistical characteristics of the mechanical processes from the macroscopic mechanical response. Nevertheless, the normalized spectra, characterized only by geometrical parameters, are more suitable because they give the probability of evolution of the internal processes without including an explicit dependence on the mechanical property under consideration. Furthermore, in the case of linear viscoelastic solids the interconversion of normalized spectra let to separate the statistical description from the intensity of relaxation Δ, which is the only macroscopic factor involved. In order to analyze this separation of variables, the interconversion of well-known distribution functions is considered. It is found that, for high values of Δ generally met in polymers, the converted spectrum of any distribution function, bounded or not, can be described virtually by a single process. This ambiguous description of the same polymeric system, given by a complex distribution and by a single process, simultaneously, is originated from the determination of Δ from the master curves. Therefore, an alternative treatment of experimental data is suggested in this paper, considering the individual curves measured at different temperatures without making any extrapolation. © 1992 The Society of Polymer Science, Japan. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00323896_v24_n1_p1_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 Dynamic mechanical properties
Linear viscoelasticity
Master curve
Relaxation and retardation spectra
Relaxation Processes - Analysis
Spectrum Analysis - Applications
Viscoelasticity - Theory
Interconversion
Linear Viscoelasticity
Macroscopic Response
Master Curves
Relaxation and Retardation Spectra
Polymers
spellingShingle Dynamic mechanical properties
Linear viscoelasticity
Master curve
Relaxation and retardation spectra
Relaxation Processes - Analysis
Spectrum Analysis - Applications
Viscoelasticity - Theory
Interconversion
Linear Viscoelasticity
Macroscopic Response
Master Curves
Relaxation and Retardation Spectra
Polymers
Povolo, F.
Hermida, ȁ.B.
Influence of intensity of relaxation on interconversion between normalized distribution functions
topic_facet Dynamic mechanical properties
Linear viscoelasticity
Master curve
Relaxation and retardation spectra
Relaxation Processes - Analysis
Spectrum Analysis - Applications
Viscoelasticity - Theory
Interconversion
Linear Viscoelasticity
Macroscopic Response
Master Curves
Relaxation and Retardation Spectra
Polymers
description Relaxation and retardation spectra comprise both the statistical processes and the macroscopic behavior of a linear viscoelastic material. Effectively, they provide the distribution function of the mechanical processes that evolve in the polymeric system and their integrals give the difference between the limiting moduli or compliances. Consequently, the normal procedure used for the interconversion between the spectra does not allow to separate the statistical characteristics of the mechanical processes from the macroscopic mechanical response. Nevertheless, the normalized spectra, characterized only by geometrical parameters, are more suitable because they give the probability of evolution of the internal processes without including an explicit dependence on the mechanical property under consideration. Furthermore, in the case of linear viscoelastic solids the interconversion of normalized spectra let to separate the statistical description from the intensity of relaxation Δ, which is the only macroscopic factor involved. In order to analyze this separation of variables, the interconversion of well-known distribution functions is considered. It is found that, for high values of Δ generally met in polymers, the converted spectrum of any distribution function, bounded or not, can be described virtually by a single process. This ambiguous description of the same polymeric system, given by a complex distribution and by a single process, simultaneously, is originated from the determination of Δ from the master curves. Therefore, an alternative treatment of experimental data is suggested in this paper, considering the individual curves measured at different temperatures without making any extrapolation. © 1992 The Society of Polymer Science, Japan.
format JOUR
author Povolo, F.
Hermida, ȁ.B.
author_facet Povolo, F.
Hermida, ȁ.B.
author_sort Povolo, F.
title Influence of intensity of relaxation on interconversion between normalized distribution functions
title_short Influence of intensity of relaxation on interconversion between normalized distribution functions
title_full Influence of intensity of relaxation on interconversion between normalized distribution functions
title_fullStr Influence of intensity of relaxation on interconversion between normalized distribution functions
title_full_unstemmed Influence of intensity of relaxation on interconversion between normalized distribution functions
title_sort influence of intensity of relaxation on interconversion between normalized distribution functions
url http://hdl.handle.net/20.500.12110/paper_00323896_v24_n1_p1_Povolo
work_keys_str_mv AT povolof influenceofintensityofrelaxationoninterconversionbetweennormalizeddistributionfunctions
AT hermidaab influenceofintensityofrelaxationoninterconversionbetweennormalizeddistributionfunctions
_version_ 1807321216845873152