Damage Tolerance of Carbon Fabric/Epoxy Composite for Korean Tilting Train Carbody

摘要

Interlaminar fracture behavior of carbon fabric/epoxy composite, which is one of the candidate composites for the Korean tilting train carbody, was investigated. Specimens were made of a CF3227 plain fabric with an epoxy resin. An initial starter crack was formed by inserting a 12.5μm thick Teflon film at the one end of the specimen. Interlaminar fracture toughness was evaluated using the mixed mode flexural fixture, which provides a wide range of mixed mode deformation by varying the length of lever arm. According to the results, the crack growth was progressive and stable under mode I dominantly mixed mode ratio and was relatively rapid and unstable under mode Ⅱ dominantly mixed mode ratio. The mixed mode interlaminar fracture behavior can be predicted by a mixed mode fracture criterion depending on the point at which the crack growth was associated.