Modeling of the thermomechanical behavior of an epoxy resin subjected to elevated temperatures and experimental verification

This work presents a study of the thermo-mechanical behavior of an epoxy resin. An experimental setup was initially developed to perform mechanical tests on polymers at high temperature. The setup allowed applying complex stress and temperature histories while delivering precise load, strain, temperature and displacement measurement. The setup was used to investigate the response of the epoxy resin through both unixial isothermal creep-recovery tests as well as time varying stress and temperature histories.;The material response was predicted using a new Schapery-type constitutive model. Characterization of the epoxy resin was firstly done using isothermal creep and recovery data at different temperatures and stress levels. The accuracy of this standard modeling approach was then validated under complex loading and temperature histories. Next, data coming from transient stress and temperature load histories were used together with isothermal creep and recovery curves to obtain the material parameters. Results shown that the approach did not significantly help obtaining a better representation of the material behavior. The parameters of the constitutive model were also obtained according to a new approach that consists of using the limited amount of data provided by one complex stress and temperature history. The model obtained was verified by comparing experimental data and predicted responses of various isothermal creep and recovery curves. Results were acceptable and represent a motivation for future research aiming at designing optimized tests to obtain reliable viscoelastic models using a limited amount of experimental data.