CORRELATION BETWEEN MECHANICAL PROPERTIES AND ACOUSTICAL ANISOTROPY IN PRESTRAINED PLATE

Abstract Nondestructive evaluation of mechanical properties in plastically deformed states using ultrasonic shear waves is discussed. Round bar tension tests, Charpy V impact tests and ultrasonic wave velocity measurements are reported on mild steel plate (SS41), high strength steel plate (HT80) and aluminum alloy plate (A5083), prestrained in tension under various conditions. Correlations between the results of the material tests and acoustical anisotropy are examined. The material dependence of the relation between material property and ultrasonic measurements is also investigated.In the plate prestrained up to the plastic region. strength increases and ductility decreases withincreasing prestrain. Though the acoustical anisotropy increases with increasing prestrain in 5541 and HT80, the opposite result is obtained in A5083. Relationships between mechanical properties and the acoustical anisotropy, in all the plates prestrained up to the plastic region, are represented approxirnately by straight lines or smooth curves. Using these results, mechanical properties of prestrained materials can be estimated nondestructively from the acoustical anisotropy.