Application of Raman Spectroscopy to the Measurement of Strains Near Crack of CFRP

Application of Raman spectroscopy to measure strains of such Raman-inactive materials as Carbon Fiber Reinforced Plastics (CFRP) was proposed by depositing Raman-active thin films. Thin films of PbO were deposited on the surface of CFRP using physical vapor deposition (PVD). The relation between peak shift of thin films of PbO and tensile strain was experimentally determined. Fracture toughness of Mode I by DCB specimens made of multidirectional CFRP was examined using Raman spectroscopy. Strain distributions near the crack tip of CFRP were measured by Raman spectroscopy. The fracture toughness of CFRP was determined using the measured results of strain distributions. These results coincided with the results by the conventional experimental method of DCB specimen and numerical analyses of Finite Element Method (FEM).