scholarly journals Numerical simulation of the thermodependant viscohyperelastic behavior of polyethylene terephthalate near the glass transition temperature: Prediction of the self-heating during biaxial tension test

2013 ◽  
Vol 53 (12) ◽  
pp. 2683-2695 ◽  
Author(s):  
Yun-Mei Luo ◽  
Luc Chevalier ◽  
Françoise Utheza ◽  
Eric Monteiro
Keyword(s):  
Numerical Simulation ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Polyethylene Terephthalate ◽  
Biaxial Tension ◽  
Tension Test ◽  
The Self ◽  
Temperature Prediction ◽  
Self Heating

scholarly journals Numerical Simulation of the Viscohyperelastic Behaviour of PET near the Glass Transition Temperature

2012 ◽  
Vol 504-506 ◽  
pp. 1139-1144
Author(s):  
Yun Mei Luo ◽  
Luc Chevalier ◽  
Eric Monteiro
Keyword(s):  
Numerical Simulation ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Biaxial Tension ◽  
Green Tensor ◽  
Biaxial Testing ◽  
Time Step ◽  
Moulding Process ◽  
Non Linear

The presentation deals with the non linear strongly elastic and viscous behaviour of poly ethylene terephthalate near the glass transition temperature and biaxially stretched at high strain rates representative of the injection stretch blow moulding process. A non linear visco-hyperelastic model inspired from [1] and identified from the experimental results of the equi-biaxial tension test [2], have been developed and presented in [3] is implemented into a finite element code developed with Matlab. The thermal behaviour modelling, identification and simulation has also been managed. First, a numerical simulation of 2D plane stress case has been performed involving 2 fields (global velocity V and elastic Cauchy Green tensor Be). Rectangular finite elements with quadratic and linear interpolations have been employed for velocity and the elastic left Cauchy Green tensor. Second, an axi symmetric formulation involving 4 fields (global velocity V, lagrange multiplier p associated with the global incompressibility condition, and multiplier q associated with the incompressibility of the elastic part) has been performed using rectangular elements. Degree of interpolation have been tested for all possible combinations to test the LBB like condition. Both simulations are compared with equi biaxial or sequential biaxial testing in order to reproduce the strain hardening effect and the self-heating observed. The final goal of this work is to perform the free blowing simulation to compare with experimental data. Therefore, we should solve an iterative procedure for a thermo-mechanical equation. At each time step, a four-field approach is adopted for the mechanical part, and a classical heat transfer equation is discretised for the thermal part.

scholarly journals Glass transition temperature prediction of polymers through the mass-per-flexible-bond principle

Polymer ◽  
2007 ◽  
Vol 48 (20) ◽  
pp. 6115-6124 ◽  
Author(s):  
J. Schut ◽  
D. Bolikal ◽  
I.J. Khan ◽  
A. Pesnell ◽  
A. Rege ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Temperature Prediction

Thermal and Radiation Effects in the Range of the Glass Transition Temperature Tg

1988 ◽  
Vol 127 ◽  
Author(s):  
G. Malow
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
High Temperatures ◽  
Transformation Temperature ◽  
Radiation Effects ◽  
Waste Form ◽  
Self Heating ◽  
Glass Transformation

Licencing procedures for the disposal of vitrified HLW require that there should be no unforeseen changes in the product properties prior to and after emplacement of the waste. Such changes could occur upon deliberate or accidental self-heating of the glass up to or even beyond the glass transformation temperature, Tg, over extended periods of time. Hence, an evaluation of the consequences of excessively high temperatures in the waste form is necessary.

Physical Modelling and Identification of Polymer Viscoelastic Behaviour above Glass Transition Temperature and Application to the Numerical Simulation of the Hot Embossing Process

2013 ◽  
Vol 554-557 ◽  
pp. 1763-1776 ◽  
Author(s):  
Gang Cheng ◽  
Jean Claude Gelin ◽  
Thierry Barrière
Keyword(s):  
Numerical Simulation ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Maxwell Model ◽  
Hot Embossing ◽  
Finite Element Software ◽  
Generalized Maxwell Model

The experimental processing parameters, such as applied pressure and forming temperature have been analysed during polymer hot embossing of micro-cavities. The viscoelastic characteristics of polymer above the glass transition temperature have been investigated with the classical viscoelastic models. Generalized Maxwell Model has been used to describe polymer behaviours in the glass transition temperature range. The parameters include relaxation time, storage modulus and loss modulus of the Generalized Maxwell Model that have been introduced. The identification of polymer characteristics has been carried out through Dynamic Mechanical Analysis (DMA). The storage modulus, the loss modulus and the damping factor of the selected polymer have been obtained with different imposed frequencies. The master curve of complex modulus has been obtained by applying the time temperature superposition principle. The experimental data has been identified with optimized fitting parameters of Generalized Maxwell Model. A proper agreement between the experimental measurement and the identification of viscoelastic model is observed. The resulting constitutive equations have been implemented in finite element software in order to achieve the numerical simulation of the hot embossing process.

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