A new insight into impact of thermal cycling on the un-notched and circular hole polymeric composite rings via naval ordnance laboratory-ring test

Abstract

In this paper, different mechanical responses of polymer matrix composite rings under thermal cycling are analyzed. The polymer matrix composite rings are classified to un-notched and open-hole specimens and tested based on the naval ordnance laboratory-ring tensile test method. Internal pressure, fracture and surface degradation changes as a function of the hole diameter and number of cycles are investigated. Experimental results suggest that specimens with larger hole radius have more mechanical property variations during thermal cycling. Also, it is revealed that the mechanical properties of laminates degrade as a function of the number of cycles and the hole diameter. The results also demonstrate that long splitting fiber breakage is the main mode for the failure of un-notched specimens, whereas fiber breakage and fiber matrix debonding are the two main modes for the failure of open-hole specimens. Finally, a multiple regression model is proposed to predict the tensile response of un-notched and open-hole polymer matrix composite rings subjected to thermal cycling condition.