Accession Number:

ADA164490

Title:

An Analysis of Symmetric Reinforcement of Graphite/Epoxy Honeycomb Sandwich Panels with a Circular Cutout under Uniaxial Compressive Loading,

Descriptive Note:

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

Report Date:

1985-12-01

Pagination or Media Count:

343.0

Abstract:

An experimental and computational analysis was made of stressstrain concentrations around a reinforced circular 1.00 inch diameter circular cutout in HMF330C34 cloth graphiteepoxy GEp and fiberglassphenolic honeycomb sandwich panels under uniaxial compressive loading. The test specimens were 10.00 in. x 8.50 in., eight ply quasi-isotropic panels. The reinforcement consisted of either one or two additional GEp plies co-cured to the outside of each facesheet. Three general reinforcement configurations were considered round, square and strips parallel to the applied load. The analytical results demonstrated that small amounts of reinforcement could greatly increase the strength-to-weight ratio. The indication was that concentrating the reinforcement close to the cutout yielded the greatest decrease in stress concentration. A computer program of experimental validation of the analytical results experienced some problems with premature panel failure caused by the facesheets separating from the core. It generally confirmed the analytical results, however. Further experimental tests on promising reinforcement configurations are justified based on these results. Properly designed reinforcement around cutouts in composite panels can significantly reduce the stress concentration and holds the promise of far lighter and stronger aerospace structures. Author

Subject Categories:

  • Laminates and Composite Materials
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE