Numerical simulation of self heating during stretch blow moulding of PET: viscohyperelastic modelling versus experimental results

Abstract

During the stretch blow moulding (SBM) process of polyethylene terephthalate (PET) bottle, high viscous dissipation generates self heating phenomena. Since the influence of temperature on polymer’s behavior is important, it is necessary to evaluate the self heating values in order to manage accurately the simulation of the process. An anisotropic visco-hyperelastic model has been developed to manage numerical simulations of free blowing. The model takes into account the anisotropy and the effect of the temperature. It has been computed in a user-interface VUMAT implemented in the software ABAQUS/Explicit. The identification of the model is based on experimental data of biaxial tension tests. We identified the characteristics taking into account the self-heating effect by a semi analytical process followed by an adjustment using finite element. For sake of validation, PET preforms have been blown from different initial temperature and followed using a thermal camera. The increase of temperature is measured by comparing initial temperature and final temperature. Comparison between the experimental and numerical simulations is discussed and influence of initial temperature or blowing pressure is highlighted in a large numerical investigation.