Vibration Analysis and Nondestructive Testing Using Double-Exposure Holographic Techniques.

摘要

Double-exposure holograms were made of aluminum 2024-T4 rectangular plates. The double-exposure technique was applied to an aluminum plate in a nonflawed and then a flawed condition. Results of these experiments, comparing the effects at various resonant frequencies, were then compared with results previously obtained in other studies to ascertain their applicability to Naval Engineering. The plate was then flawed with a 1 inch through-thickness vertical slit, and double-exposure holograms were generated. The resonant frequencies of the flawed plates were recorded, and the mode shape deviations were analyzed. A comparison was made of resonant frequencies and mode shapes of flawed and nonflawed plates to determine the applicability of holographic procedures to nondestructive testing of vibrating mechanical parts. Results of the experiments indicate that holographic nondestructive testing (HNDT) of vibrating objects in a shipboard environment holds promise for future applications. Further research is required to develop systems for use aboard ships. These procedures are being used successfully in the aerospace industry and automobile manufacturing. (Author)