Material characterization and residual stresses simulation during the manufacturing process of epoxy matrix composites

A thermal, rheological and mechanical material characterization of an aeronautic epoxy resin from commercial prepreg is reported in this article. The kinetic of the crosslinking reaction of the resin is characterized and modeled. The specific heat, the glass transition temperature, the thermal expansion coefficients, the chemical shrinkage coefficients and the thermo-mechanical properties have been investigated as a function of temperature and degree of cure. Dynamic mechanical measurements are used to determine the gel point. Finally, the residual stresses developed during the curing process are calculated using a finite element simulation, taking into account the material properties evolutions according to proposed models. The results highlight the importance of the characterization accuracy and the associated models.