Abstract
Changes of thermal property and flexure strength of CFRP, which was fatigued with heat cycle by using a newly-made heat cycle testing equipment, have been investigated systematically by varying the condition of degradation.
In CFRP, three peaks were observed in the damping curve when subjected to fatigue with heat cycle. The changes of damping curves and fracture surfaces suggest that the matrix region of CFRP may be classified into three groups, i.e. the regular matrix region, the surface region of fillers and the stratified region which surrounds fillers. The degradation of CFRP with heat cycle fatigue seemed to occur from the degradation of the regular matrix region. The degradation of CFRP causes the decrease of the first peak of damping curve and the lowering of flexure strength. The damping curves of other two regions did not change with fatigue. It is concluded that the existence of other two regions, i.e. the surface region of fillers and the stratified region which surrounds fillers, plays a major role against the durability for fatigue and the retention of strength of CFRP.
