Interlaminar fracture toughness of CFRP in mode I and mode II determined by Raman spectroscopy

Fracture toughness of multidirectional Carbon Fiber Reinforced Plastics (CF RP) for Mode I and Mode II was investigated using Double Cantilever Beam (D CB), End Notched Flexure (ENF) specimens and Raman Coating Method. The dist ribution of strain near the crack tip of CFRP was measured by Raman spectro scopy. Thin films of PbO on the measured surface of the DCB and ENF specime ns were deposited by physical vapor deposition as the pretreatment to measu re the strain by Raman spectroscopy. The fracture toughness of multidirecti onal CFRP in both Mode I and Mode II was determined using the results measu red by Raman spectroscopy. This result coincided with those measured by con ventional methods. (C) 2001 Elsevier Science Ltd. All rights reserved.