Performance of a parallel viscoelastic-viscoplastic model for a microcellular thermoplastic foam on wide temperature range

Abstract

This paper is concerned with the experimental testing and the constitutive modelling of a thermoplastic microcellular polyethylene-terephthalate (MC-PET) foam on the temperature range of 21-210 � C in order to investigate the temperature-dependent performance of the applied parallel viscoelastic-viscoplastic material model. By means of carefully designed uniaxial mechanical tests in temperature chamber, the viscous, elastic and yielding behaviours of the investigated material are identified, which are then applied for selecting suitable viscoelastic-viscoplastic constitutive models. The material characterization process is conducted using finiteelement-based fitting method, including also the analysis of the applied numerical optimization algorithm. The fitting results are used to analyse the parameter sensitivity and to propose closed-form analytical relations for the temperature dependency of the material parameters. Finally, the utilisation of the analytical temperature functions for speeding up the parameter-fitting process is also demonstrated.

Effect of micro-aeration on the mechanical behaviour of chocolates and implications for oral processing

“…In the three-dimensional formulation, the two-layer viscoplastic model is combined with the Von Mises yield criterion. 90 The elastic-plastic layer defines the time-independent behaviour of the material and is based on the Von Mises yield condition. The elastic-plastic element consists of an elastic component described by an elastic modulus E ep in series with a plastic component represented by a parallel combination of a sliding element to model the yield stress σ yo and a spring H′ representing the strain hardening effect in the plastic region which is activated when the yield stress is reached.…”

Large deformation analysis of a backside-supported snap-fit with nonlinear behavior

“…Several studies have investigated the mechanical behavior of polymers over the past few decades, and various constitutive models have been proposed to describe the characteristic of the material [ [13] , [14] , [15] , [16] , [17] ]. These models can be programmed using in-house code or in the form of a user subroutine in commercial finite element analysis (FEA) software [ 18 , 19 ]. When an FEA model is used to analyze time-dependent history, it requires a complicated constitutive model with several parameters that need to be determined experimentally.…”

A General Temperature-Dependent Stress–Strain Constitutive Model for Polymer-Bonded Composite Materials

“…By compounding different filler materials with polymer, new functional materials can be made, providing a viable technology for on-demand material design and engineering [ 1 ]. Applications of PBMs include, but are not limited to, polymer-bonded magnetics [ 2 , 3 ], energetics [ 4 , 5 ], aluminum [ 6 ], fiber [ 7 , 8 ], and many others [ 9 , 10 , 11 ]. To utilize those functional materials in critical applications, understanding their mechanical properties and deformation behaviors under different loading and temperature conditions is of great importance in meeting the basic design criteria.…”