Accession Number : ADA190617

Title :   A Study of Damage Tolerance in Curved Composite Panels.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Wilder, Brendan L

PDF Url : ADA190617

Report Date : Mar 1988

Pagination or Media Count : 152

Abstract : As more and more composite materials are used in modern aircraft construction, the understanding of the damage tolerance of this relatively stiff, brittle, anisotropic material becomes important to designers. This thesis investigated the behavior of a cylindrical composite panel made of AS4/3501-6 graphite/epoxy with ply orientations. Abrasion and burn surface damage was physically modeled in the panels. The panels were then tested by compressively loading them and a comparison was made to buckling predictions obtained. These tests indicated that panels which have suffered minor surface damage do not deviate significantly from buckling predictions. Composite laminates subjected to a low speed impact, such as a dropped tool or a manufacturing load, often develop an internal delamination. Since curved panels are 3-dimensional, and buckling is a non-linear phenomenon, the compressive load which will cause curved panels to become unstable is extremely hard to predict analytically. This thesis presents a technique whereby the local buckling loads at the delamination may be predicted using a 2-dimensional model with a plane strain correction.

Descriptors :   *COMPOSITE MATERIALS, *AIRCRAFT PANELS, ABRASION, ANISOTROPY, BRITTLENESS, BUCKLING, COMPOSITE STRUCTURES, COMPRESSIVE PROPERTIES, CONSTRUCTION, CYLINDRICAL BODIES, DAMAGE, LAMINATES, LOADS(FORCES), MANUFACTURING, STIFFNESS, SURFACES, CARBON REINFORCED COMPOSITES, TUBULAR STRUCTURES, GRAPHITED MATERIALS, IMPACT STRENGTH, THESES, TOUGHNESS, AIRFRAMES, STRENGTH WEIGHT RATIO, COSTS, MAINTENANCE

Subject Categories : Laminates and Composite Materials
      Aircraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE