Research on Exploratory Development of Nondestructive Methods for Crack Detection. Part III.

摘要

Results of a research study devoted to exploratory development of a nondestructive method for crack detection are reported. The method investigated is based upon an Acoustic Impact Technique (AIT),which consists of the analysis of the vibrations in the test specimens produced by mechanical pulses. The 'time-to-damp'of these vibrations was the primary factor evaluated. General design considerations for the test probes are discussed. The possibility of improving the accuracy and sensitivity of the AIT by a Damping Decrement Computer was investigated and a breadboard model constructed. Fatigue crack investigations were performed and the AIT-measurements correlated with fatigue cycles,crack detection and crack growth. (Author)