Development of Nondestructive Testing Techniques For Detecting Stress in Ferromagnetic Materials

摘要

The overall objective of the present program was to investigate the fundamental aspects of the Barkhausen effect with the ultimate goal of more effectively exploiting this effect as a means of measuring applied and residual stresses in ferromagnetic materials. Two experimental methods were employed in the investigation: (1) application of a multichannel pulse height analyzer to the study of certain statistical properties of the voltage pulses induced in a search coil by Barkhausen jumps; and (2 application of the Kerr magnetooptic effect to optically image magnetic domain structure and to study the effects of stress thereon by high-speed motion picture photography.