Accession Number : ADA188513

Title :   Low Velocity Impact of Composite Aerostructures.

Descriptive Note : Final rept. Sep 83-Sep 85,

Corporate Author : VILLANOVA UNIV PA

Personal Author(s) : McLauglin, Philip V , Jr

PDF Url : ADA188513

Report Date : Sep 1986

Pagination or Media Count : 285

Abstract : While considerable effort has been put into understanding the low velocity impact of composite laminates, there is still considerable uncertainty concerning the analysis tools required to give accurate predictions of stresses and strains for design purposes. It has been determined that elastic bending solutions are inaccurate, and that several phenomena may explain the differences observed between elastic theory and experiment. These are: 1. Contact deformations, 2. Transverse shear deformations, 3. Viscoelasticity, 4. Large deflections and membrane effects. The objective of this project is to determine if and under what conditions each of the four phenomena must be modeled in analyses of low velocity impact of fiber composite laminated structures. The program has shown that the flexural viscoelasticity is negligible, but that viscoelastic transverse shear and contact deformations are important for short composite plates. It appears that membrane effects may be important for longer plates where strains are significantly underpredicted by elastic small deflection analysis. These results will give guidance to analysts who must predict strains and stresses in order to achieve safe, efficient,impact resistant composite structures. Keywords: Military aircraft, Penetrator, Delamination, Laminates, Arsenic, Airfoils.

Descriptors :   *AIRFOILS, *COMPOSITE MATERIALS, *COMPOSITE STRUCTURES, *FIBER REINFORCED COMPOSITES, *EPOXY COMPOSITES, *BEAMS(STRUCTURAL), BENDING, DEFLECTION, DEFORMATION, ELASTIC PROPERTIES, FLEXURAL PROPERTIES, LAMINATES, LOW VELOCITY, MILITARY AIRCRAFT, PLATES, SHEAR PROPERTIES, STRESSES, VISCOELASTICITY, IMPACT STRENGTH, TOUGHNESS, GRAPHITED MATERIALS, IMPACT TESTS, PENETRATION, FINITE ELEMENT ANALYSIS

Subject Categories : Aircraft
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE