Continuum Damage Mechanics for Creep Lifetime Estimation in Polymer Matrix Composites at Various Temperatures

Nowadays, composites have great applications in mechanical structures due to their proper ratio of the strength to the weight. Such application includes automotive and aerospace industries. These components may be affected by the creep phenomenon, when they work at high temperatures. Therefore, there should be appropriate creep behavior of materials for these parts. In this article, the Continuum Damage Mechanics (CDM) method was used to calculate the creep lifetime of various polymer matrix composites. For this objective, experimental data were utilized from creep tests in the literature, on standard specimens, at different temperatures. Then, the relation between the stress, the temperature and the lifetime was presented by the CDM approach, which was calibrated by experimental results. In addition, the Levenberg-Marquardt method was employed to optimize the creep lifetime equation and to find temperature-dependent material constants. Consequently, the obtained results showed that there was a good agreement between experimental and calculated creep lifetimes of composites.