Comparison on Mode I and Mode II Interlaminar Fracture Toughness of Composite Plates according to Curvature Changes

This paper compared the mode I and mode II interlaminar fracture toughness of composite plates in relation to curvature changes. The curvature was set at R1/1,500 mm, R1/1,700 mm, R1/1,900 mm, and R1/2,100 mm depending on the pressure vessel size, and mode I and mode II tests were conducted on plates with and without curvature. The specimens were DCB and ENF, and the laminate angle was fixed at 0 degrees to minimize angle-related changes. The tests were carried out in accordance with ASTM D5528 and D6671/D6671M. The results showed an increase in interlaminar fracture toughness with increasing curvature for mode I tests, but no difference for mode II. The results of this paper can be used for accurate prediction of progressive failure of pressure vessels and composite structure with curvature.

Automated summary

This paper compared the effect of curvature changes on the mode I and mode II interlaminar fracture toughness of composite plates. The results showed that the interlaminar fracture toughness increased with increasing curvature for mode I tests, but there was no difference for mode II tests. These findings are important for accurately predicting the progressive failure of pressure vessels and composite structures with curvature.