Thermo-mechanical Viscoelastic, Viscoplastic, and Viscodamage Model for Polymers and Polymer Composites

Abstract

Listen

Translate article

Polymer and polymer composite materials offer a wide range of advantages high such as strength-to-weight ratio, impact resistance, highflexibility , recyclability, corrosion resistance, low cost and fast processing times, make them very attractive which materials [1, 2]. The vast applications of using materials in such common and highboth tech industries exhibit the -importance of establishing and using accurate, simplereliable, , and practical numerical models to simulate and predict the behavior of ese materials. There are numerousth experimental observations indicating the nonlinear behavior of polymers and polymer composites in different loading conditions, especially high temperatureat s or high stress levels[3, 4]. Due to the complex behavior of materials especially these the challenges in the modeling damage ofnucleation and growth that depends on rate of loading,temperature, and the history of deformation, much less emphasis has been placed on predicting the damage evolution and fracture of polymer and polymer composites. Moreover, the combination of non-linear thermo-viscoelasticity, thermo-viscoplasticity, and rate- and temperaturedependent damage (thermo- -viscodamage) effects seems unavoidable. Reviewing the available publications in the open literature on this of materials fieldsurprisingly reveals that, even though there are several damage models for polymers, few works have been done for developmentthe of such numerical models to couple the viscoelastic, viscoplastic, and damage effects as a comprehensive model for predicting the mechanical responses and actual behavior of polymers at different temperatures, stress levels, and strain rates. To bridge this gap combination of , a Schapery’s nonlinear viscoelasticity - [5] and the Perzyna’s viscoplasticity constitutive model[6] s along with viscodamage model the recently proposed by Darabi et al. [7] have been utilized in this study for modeling the nonlinear behavior of polymers and polymer composites at different loading conditions and temperatures. The presented thermo-viscodamage model is a function of temperature, total effective strain, damage history, and the damage driving force expressed in terms of thdeviatoric e stress invariants in the undamaged configuration.This expression for the damage force enables the distinction between the influence of compression and extension loading conditions on damage nucleation and evolution. Also, the ability of the constitutive model for predicting the tertiary creepwhich , shows the non-linear behavior of polymers during damage nucleation and growth, is presented.