Accession Number : AD0783504

Title :   Three-Dimensional Analysis for the Stress Distribution Near Circular Holes in Laminated Composites.

Descriptive Note : Interim rept.,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF ENGINEERING SCIENCE AND MECHANICS

Personal Author(s) : Dana,Jon R. ; Barker,Richard M.

Report Date : AUG 1974

Pagination or Media Count : 42

Abstract : A three-dimensional finite-element solution for the state of stress in a laminated composite with a circular hole, loaded in axial extension, is presented. Each layer of the laminate is assumed to be homogeneous and to have orthotropic properties. A curved isoparametric element with 24 nodal points and 72 degrees-of-freedom is used to model the individual layers of the laminate. The nodal displacements are determined by minimizing the total potential energy of the system at the element level with a conjugate gradient iterative method. Three symmetric stacking sequences ((0/90)s, (90/0)s and (- 45/+45)s) are investigated for both thick and thin boron-epoxy laminates. The results presented include inter-laminar stresses in the vicinity of a circular hole in the laminate. (Author-PL)

Descriptors :   *LAMINATES, *COMPOSITE MATERIALS, *STRESS CONCENTRATION, STRESSES, HOLES(OPENINGS), BORON, EPOXY RESINS, NUMERICAL ANALYSIS, THREE DIMENSIONAL

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE