Accession Number : AD0756454

Title :   Three-Dimensional Analysis of Stress Concentrations Near Holes in Laminated Composites,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG COLL OF ENGINEERING

Personal Author(s) : Barker,Richard M. ; Dana,Jon R. ; Pryor,Charles W. , Jr

Report Date : DEC 1972

Pagination or Media Count : 32

Abstract : Stress concentration factors are determined using a three-dimensional finite-element analysis for laminated composites pierced by circular, square and diamond-shaped holes. Both angel-ply and bidirectional laminates are investigated for hole size to width-of- strip ratios from 0.125 to 0.41. Normal stress concentrations are found to be the least for square holes and greatest for diamond-shaped holes. Interlaminar shear stress concentrations which cannot be determined by a two-dimensional analysis, are as large at the hole surface as those at the free edge when angle-ply laminates are utilized and the holes are large. For small circular holes, angle-ply (+ or -45) LAMINATES ARE RECOMMENDED. When large holes are present, bidirectional (90/0) laminates are shown to be more efficient. (Author-PL)

Descriptors :   (*COMPOSITE MATERIALS, STRESSES), LAMINATES, ORIFICES, NUMERICAL ANALYSIS

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE