The relationship between the self-heating behavior and damage mechanism of carbon fiber/epoxy composites subjected to random vibration fatigue

Non-destructive thermal imaging-based internal damage identification and fatigue life assessment in composites necessitates investigating the relationship between the self-heating behavior and damage mechanisms. This study develops a novel self-heating numerical algorithm that categorizes temperature rise contributions into three components: (I) the viscoelastic deformation of composites, (II) interface debonding slip friction, and (III) delamination friction. The viscoelastic response of the composite was characterized by modifying the viscoelastic standard linear solid model, coupled with a damage model to investigate the temperature evolution of laminates during random vibration fatigue, and a series of verification experiments were carried out. Furthermore, the dynamic characteristics degradation patterns and damage-damping effect of composite laminates were explored in depth. The results demonstrated that temperature evolution significantly depends on the damage propagation; the viscoelastic deformation serves as the primary heat source driving the self-heating behavior of the composite, resulting in uniform thermal distribution within the region of interest. The internal damage modifies the relative contributions to temperature rise, thereby changing the surface thermal distribution of the composite. Dominant damage modes exhibit stage-dependent characteristics that differentially govern temperature evolution throughout the loading history. The developed self-heating model provides novel possibilities for accurate identification of internal damage and high-cycle fatigue life prediction in composite structures.