Accession Number : ADA263170


Title :   Enhanced Noncontacting Laser Extensometer for Biaxial Strain Measurements


Descriptive Note : Final rept. Jan-Aug 1992


Corporate Author : OPTRA INC BEVERLY MA


Personal Author(s) : Connolly, James J ; Engel, James R ; Lintz, Andrew T


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a263170.pdf


Report Date : Sep 1992


Pagination or Media Count : 42


Abstract : In the proposed program, OPTRA will develop and commercialize a non- contact biaxial extensometer for the material testing market. The optical technology, based on an existing OPTRA single axis product, allows the accurate measurement of surface strains on any test specimen without contact and without material preparation. The non-contact measurement in ideal for high temperature testing, single fiber testing, high humidity/liquid immersed testing, high strain elastomer testing and many other applications that are unsuitable for bonded gages. The incorporation of two axes of strain measurement in a single instrument allows users to measure shear strain, Poisson's ratio, and other biaxial strain conditions. The ability to reorient the measurement axes relative to the test specimen in real time with small cyclic loading allows the user to rapidly identify the maximum and minimum normal strain axes and thereby fully define an unknown state of plane strain. The product development will be focused on meeting a wide range of material test requirements and on keeping production costs low to insure that a commercially viable product is produced... . Strain measurements, Poisson's ratio, Noncontact measurements, Laser extensometer, Mechanical testing, Biaxial strain.


Descriptors :   *OPTICAL IMAGES , *LASER BEAMS , *STRAIN RATE , *EXTENSOMETERS , *STRAIN GAGES , TEST AND EVALUATION , SIGNAL PROCESSING , DATA PROCESSING , REQUIREMENTS , LIGHT SCATTERING , MEASUREMENT , OPTICAL PROPERTIES , HIGH HUMIDITY , POISSON RATIO , BIAXIAL STRESSES , BREADBOARD MODELS , SHEAR STRESSES , SURFACES , COSTS , LASERS , TEMPERATURE , FIBERS , REAL TIME , HIGH TEMPERATURE , DEFORMATION , ELASTOMERS


Subject Categories : Lasers and Masers
      Test Facilities, Equipment and Methods
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE