SHEAROGRAPHY FOR NON-DESTRUCTIVE BOND EVALUATION FOR SUBMARINE HULL COATINGS

This proposal aims to develop and adapt a novel optical technique called digital shearography for non-destructive bond evaluation of submarine hull coatings. Shearography is somewhat analogous to a large number of strain gages as it permits full-field measurement of strain distribution. It detects flaws in materials by-detecting flaw-induced strain anomolies. Being full-field, non-contacting, and not requiring installing strain gages, the technique appears to have the potential for development into a practical technique for nondestructive evaluation of large objects such as submarine. Despite being a young technique, shearography has already been accepted by the rubber industry for nondestructive evaluation of tires, and by the aerospace industry for nondestructive evaluation composite materials. The proposed investigation aims to prove the feasibility of extending shearography to inspecting rubber to metal bonds. The immediate goal is to accomplish the above objective, and the ultimate is to develop shearography into a fully automated and user-friendly tool for nondestructive evaluation in field/production environments.