Strain measurement for Raman-inactive substrates with PbO thin films usingRaman coating method

A new method of Raman spectroscopy to measure strain of Raman-inactive mate rials deposited with Raman-active thin films was proposed. This method is d enoted as the Raman Coating Method. This is the application of Raman spectr oscopy, in which thin films of PbO are deposited on the surface of resins a nd metals using physical vapor deposition (PVD) as the pretreatment to meas ure strain. The relation between peak shift of PbO thin films and tensile s train was experimentally examined. This relation was independent of the mec hanical properties of materials on which PbO thin films were deposited. The residual stress in PbO thin films was also measured. The absolute values o f residual stress in the films on resins were much greater than those on me tals. As an application of the proposed method, the tensile strain in carbo n fiber of carbon fiber reinforced plastics (CFRP) was measured by Raman sp ectroscopy. (C) 1999 Kluwer Academic Publishers.