Accession Number : AD0752127

Title :   Error Analysis of the Modified Ligtenberg Experimental Stress Analysis Method.

Descriptive Note : Technical rept.,

Corporate Author : ARMY MISSILE COMMAND REDSTONE ARSENAL ALA GROUND EQUIPMENT AND MATERIALS DIRECTORATE

Personal Author(s) : Schaeffel,John A. , Jr. ; Smith,Kenneth R. ; Griffin,Jodson R.

Report Date : 18 JUL 1972

Pagination or Media Count : 143

Abstract : Materials Testing has become a very expensive and time consuming procedure. To alleviate some of the expense, practical methods using the Ligtenberg Reflective Moire Technique have been developed to study plate curvatures produced by stress, strain, and static and dynamic loading. The procedure for using the Ligtenberg Reflective Moire Technique was greatly improved by Rieder and Ritter who used a partial mirror to reflect various grid patterns onto the plate. However, the partial mirror has several drawbacks which are the result of indices of refraction, nonparallelism, and thickness. These various operating characteristics result in a distorted view of the Moire fringes. The purpose of the report is to analyze the various experimental situations which are imposed on the partial mirror system and to suggest ways for correcting the various problems encountered. (Author)

Descriptors :   (*STRESSES, *NONDESTRUCTIVE TESTING), TEST EQUIPMENT, MIRRORS, OPTICAL EQUIPMENT, ALIGNMENT

Subject Categories : Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE