Accession Number : AD0651920

Title :   NEW TEST TECHNIQUE FOR SHEAR MODULUS AND OTHER ELASTIC CONSTANTS OF FILAMENTARY COMPOSITES,

Corporate Author : DOUGLAS AIRCRAFT CO INC SANTA MONICA CALIF MISSILE AND SPACE SYSTEMS DIV

Personal Author(s) : Greszczuk,L. B.

Report Date : 1967

Pagination or Media Count : 28

Abstract : A new test technique is presented for measuring the five principal elastic constants of filamentary composites: two moduli of elasticity, two Poisson's ratios, and a shear modulus. The technique employs strain rosette-instrumented tensile specimens containing oriented filaments. Transformation equations for orthotropic materials are used to develop pertinent equations for the elastic constants evaluation. Given one of the Poisson's ratios of a laminate (experimental or theoretical value) and using Maxwell's Reciprocity Theorem, principal elastic properties can be obtained from data corresponding to one tensile test. Otherwise, two tests are required to obtain those properties. The shear modulus, which is independent of the Poisson's ratio, can be obtained from tensile test data on a specimen having filaments oriented at any angle 0 < alpha < 90 degrees. The validity and consequences of using theoretical values of Poisson's ratio to compute properties other than shear modulus are discussed. (Author)

Descriptors :   (*COMPOSITE MATERIALS, ELASTIC PROPERTIES), (*ELASTIC PROPERTIES, TEST METHODS), SHEAR STRESSES, FILAMENTS, TENSILE PROPERTIES, STRAIN(MECHANICS), MODULUS OF ELASTICITY

Subject Categories : Laminates and Composite Materials
      Test Facilities, Equipment and Methods
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE