Accession Number : ADA294411

Title :   Biaxial Testing of Composites. A Study of the Disk Specimen.

Descriptive Note : Final rept. 1993-1994,

Corporate Author : ARMY RESEARCH LAB WATERTOWN MA MATERIALS DIRECTORATE

Personal Author(s) : Cavallaro, Paul ; Gee, Lisa ; Tsangarakis, Nikos

PDF Url : ADA294411

Report Date : APR 1995

Pagination or Media Count : 36

Abstract : The strain fields in composite disks loaded with a pin on one side while the other side was simply supported circumferentially, were examined. Finite Element Analysis (FEA) results indicated that in a balanced, (0(2)/90(2)2s cross-ply composite, the in-plane principal strains were nearly equal and constant within the load pin radius. For a (0/90)S/(90/0)Ss balanced laminate, FEA results indicated an equi-biaxial principal strain field within the same radius. The interlaminar shear strains were shown to be constant through the disk thickness and depended greatly on the interfiber distance and fiber diameter. It was shown that large, closely spaced fibers could intensify the shear strain field to the extent of forming single or multiple delaminations. (AN)

Descriptors :   *FINITE ELEMENT ANALYSIS, *FIBER REINFORCED COMPOSITES, *BIAXIAL STRESSES, TEST AND EVALUATION, STRESS STRAIN RELATIONS, MATHEMATICAL MODELS, DIAMETERS, THICKNESS, OPTIMIZATION, LAMINATES, STRESS TESTING, DEFORMATION, METAL MATRIX COMPOSITES, SHEAR STRESSES, INTERPOLATION, DISKS, PINS, RADIUS(MEASURE), DELAMINATION, AXIAL LOADS, GRAPHITE EPOXY COMPOSITES, SHEAR STRENGTH.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE