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Statistical Methods for Parameter Identification of Temperature Dependent Viscoelastic Models
Author(s) -
RoseroVelásquez Hugo,
Cottone Giulio,
ColinasArmijo Natalia
Publication year - 2018
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201800372
Subject(s) - viscoelasticity , creep , materials science , power law , jump , random walk , stress (linguistics) , weibull distribution , statistical physics , mechanics , mathematics , composite material , statistics , physics , linguistics , philosophy , quantum mechanics
A fully fractional stochastic model for linear viscoelastic materials is proposed. Time dependent stress‐strain response for creep tests is described through Adaptive Links theory as a random process of successive micro‐stretching events due to disentanglements between groups of material fibers. The process is modeled by a Continuous Time Random Walk (CTRW) that tends in average to power‐law function, which corresponds to the creep kernel of the usual fractional model for viscoelasticity. Thermal effects are explained through changes in waiting time and jump compliance distribution parameters. Simulated CTRWs are compared with experimental results of specimens of epoxy resin. It was observed that simulated mean function approaches to measurements in long term during the creep phase. Additionally, parameter averages decrease for higher temperatures, representing more frequent jumps of fiber creep strain and faster development of creep process.