Evaluation of Structural Degradation of Polymeric Composites Subjected to Self-Heating by the Thermal Diffusivity Analysis

A significant acceleration of degradation process is observed during occurrence of the self-heating effect, which has a character of mechanical energy dissipation and causes heating-up of structures. Following this, it is essential to evaluate a critical value of self-heating temperature at which a thermal domination of fatigue processes occurs. With a progress of degradation irreversible structural changes occur. In this study, an experimental evaluation of the degradation process was performed based on analysis of apparent thermal diffusivity of a composite structure at various self-heating temperature values. The obtained results show that the estimated apparent thermal diffusivity is a sensitive measure which allows for effective evaluation of structural changes caused by fatigue processes.