Abstract (Invited)

Nonlinearity Parameter Measurement and Characterization of Microstructural States in Solids

W.T.Yost (Nondestructive Evaluation Sciences Branch, Structures and Materials, NASA-Langley Research Center, Hampton, VA, USA)

e-mail: w.t.yost@larc.nasa.gov

Novel harmonic generation measurement techniques have been developed to obtain in-situ nonlinearity parameters of metallic materials. These techniques allow the investigator to explore the nonlinear interactions between ultrasonic waves and significant microstructures which then can be monitored during service life. Experimental arrangements are discussed and experimental results are directly compared with values predicted from theoretical calculations of the microstructural contributions in aluminum single crystals, aluminum alloys, and stainless steels. Effects of diffraction and attenuation on these measurements are discussed.

Section : 3