Visco hyperelastic constitutive model for polymer stretch blow moulding
Résumé
Within their thermoforming and stretch blow moulding range amorphous polymers are deformed while they are in their rubbery state (i.e., above glass transition temperature). In this range their mechanical behaviour results of a complex combination of hyperelastic strain and viscous or plastic components. In parallel, constitutive model should account for very specific and coupled temperature and strain rate effects. Based on experimental data obtained in monotonic and non monotonic tension over a wide range of strain rates and temperatures a revisited network model is presented that allow modelling strain rate and temperature dependence and loading unloading loops. This "visco hyperlestic" models allows 3D modeling in a thermodynamical frame and should allow easier numerical modelling though some physical aspects should be assessed now. Paper also stress on the necessary quality of experimental measurements.