Holographic Technique for Measurements of Strain

• Main Authors: Berger,R. H., Marshall,S. J., Munis,R. H., Fourney,M. E.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H
• Format: Text
• Language: English
• Published: 1975
• Subjects: Snow; Ice and Permafrost; Test Facilities; Equipment and Methods; *STRAIN(MECHANICS); *HOLOGRAPHY; *SEA ICE; MEASUREMENT; DEFORMATION; MODULUS OF ELASTICITY; TEST METHODS; INTERFEROMETRY; POISSON RATIO; Ice; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA011247; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA011247

An experimental program was carried out to see if holographic interferometry could be used to determine Young's modulus and Poisson's ratio of ice using the ring test. Spurious rigid body deflections of up to 0.5 microinch were found when the sample was compressed. These motions are of such magnitude that they will affect the accuracy of the bore gauge measurements of ice strength. The technique most suited to measurements of the deformation of the ice ring is speckle interferometry. This technique is most sensitive to motions of the magnitude found when using the ring test on ice and it allows measurement of motion in each of the three orthogonal directions separately so that Young's modulus and Poisson's ratio may be obtained easily.