SURFACE RESIDUAL STRESS ANALYSIS OF METALS AND ALLOYS

PREDICTION OF CATASTROPHIC AND COSTLY FAILURE IN STRUCTURAL COMPONENTS HAS BEEN HAMPERED BY THE INABILITY TO MEASURE STRESS LEVELS IN CRITICAL COMPONENTS WITH ACCURACY. THIS PROPOSAL DESCRIBES THE STEPS NEEDED TO DETERMINE THE FEASIBILITY TO DEVELOP A STRESS MEASUREMENT SYSTEM THAT RELIES ON ULTRASONIC (ACOUSTOELASTIC) WAVE MEASUREMENTS. THE RECENT ADVANCEMENTS MADE IN THE USE OF CRITICAL REFRACTED LONGITUDINAL WAVES (CRLW), COUPLED WITH THE EXPANSION OF COMPUTER-ASSISTED ULTRASONIC DETECTION SYSTEMS, HAVE GIVEN IMPETUS TO THIS PROPOSAL. THIS STUDY INVOLVES THE ANALYSIS OF THE CRLW PHENOMENA, TO MEASURE RESIDUAL STRESS AT THE SURFACE AND INTERIOR OF A PART OR STRUCTURE, EXPERIMENTAL VERIFICATION OF FUNDAMENTAL PREMISES, AND THE DEVELOPMENT OF A DESIGN SPECIFICATION FOR A STRESS ANALYSIS SYSTEM.