Accession Number : ADA302100

Title :   Stress Concentration Around a Small Circular Hole in the HiMAT Composite Plate.

Descriptive Note : Technical memo.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION MOFFETT FIELD CA AMES RESEARCH CENTER

Personal Author(s) : Ko, William L.

PDF Url : ADA302100

Report Date : DEC 1985

Pagination or Media Count : 18

Abstract : When an infinite isotropic plate containing a circular hole is subjected to remote uniaxial tension, the tangential stress along the boundary of the circular hole will reach a value three times the remote tensile stress at two boundary points lying on the hole diameter perpendicular to the loading axis. Namely, the maximum tangential stress concentration factor is 3, which is independent of the hole size. For anisotropic materials, such as fiber-reinforced composite materials, the picture is entirely different. The value of the maximum tangential stress concentration factor for a composite plate can be greater or less than 3, and the locations of the maximum stress points could shift depending on the loading direction and the fiber orientations. This report calculates the tangential stress distribution around a circular hole in a composite plate (single ply or laminated) and examines how the maximum stress points shift with the fiber orientations. In addtion, the dependency of the stress concentration factor on the hole size is examined. In the analysis, the composite system is treated as a continuous anisotropic plate having effective elastic properties. The calculated stress concentration factors are then compared with experimental data. (MM)

Descriptors :   *COMPOSITE STRUCTURES, *HOLES(OPENINGS), *GRAPHITE EPOXY COMPOSITES, *STRESS CONCENTRATION, MANEUVERABILITY, COMPOSITE MATERIALS, LAMINATES, TENSILE STRESS, FIBER REINFORCED COMPOSITES, ELASTIC PROPERTIES, MODULUS OF ELASTICITY, ORIENTATION(DIRECTION), PLATES, ANISOTROPY, SHEAR STRESSES, TANGENTS, FLIGHT MANEUVERS, POISSON RATIO, CIRCLES.

Subject Categories : Laminates and Composite Materials
      Aircraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE