Accession Number : AD0770108

Title :   Nondestructive Determination of Surface Flaw Geometry by Acoustical Holography, Exploratory Development.

Descriptive Note : Final rept. 3 Jan 72-2 Jan 73,

Corporate Author : WASHINGTON UNIV SEATTLE AEROSPACE RESEARCH LAB

Personal Author(s) : Fourney,M. E. ; Auth,D. C. ; Intlekofer,M. J. ; Kobayashi,A. S.

Report Date : JUN 1973

Pagination or Media Count : 37

Abstract : The results of experiments aimed at developing a new nondestructive method of investigating surface flaw geometry based on acoustical holography and a newly proposed liquid crystal read-out device are presented. The liquid crystal area detector was show to be feasible for use with acoustical holography; however, it was not applied to the monitoring of surface flaw geometry. The method was shown to have an order of magnitude improvement in resolution capabilities; however, it was found to be severely lacking in the area of sensitivity, re-sponse time, and dynamic range. A strict thermal activation of the liquid crystals by the ultrasound was found not to be the optimum. (Author-PL)

Descriptors :   *Ultrasonic tests, *Fracture(Mechanics), *Holography, Ultrasonic radiation, Liquid crystals, Crack propagation, Surfaces, Aluminum, Steel, Quartz, Test equipment, Stresses

Subject Categories : Metallurgy and Metallography
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE