Evaluation of viscoelastic-viscoplastic characteristics and finite element analyses for thermoplastics. (3rd May 2020)

• Record Type: Journal Article
• Authors: Takaoka, Haruki; Sakaue, Kenichi
• Is Part Of: Advanced composite materials. Volume 29:Number 3(2020)
• Page Start: 273
• Page End: 284
• Publication Date: 2020-05-03
• Subjects: Viscoelasticity -- viscoplasticity -- thermoplastics -- finite element analysis -- material testing; Composite materials -- Periodicals; Reinforced plastics -- Periodicals; Electronic journals; 620.11805
• DOI: 10.1080/09243046.2019.1699268
• Languages: English
• ISSNs: 0924-3046

Abstract

Abstract : Thermoplastics are viscoelastic-viscoplastic materials whose mechanical behavior depends on temperature and strain rate. In this study, the viscoelastic-viscoplastic characteristics of polybutylene terephthalate (PBT) are evaluated on the basis of the mechanical model consisting of Schapery nonlinear viscoelasticity and Perzyna viscoplasticity. Also, the viscoelastic-viscoplastic behavior of the PBT is predicted by finite element simulation. The evaluation reveals that the initial yield stress depends on temperature and strain rate; however, viscosity depends on only strain rate. Furthermore, the rate sensitivity is independent of temperature and strain rate. The finite element simulation using identified viscoelastic-viscoplastic characteristics can reproduce the stress–strain relationship in the uniaxial tensile tests under various testing conditions. It is expected that the time-temperature superposition principle can be applied to not only the maximum stress but also the initial yield stress.