Moisture and Temperature Effects on the Instability of Cylindrical Composite Panels.
Abstract
An analytical investigation was performed to evaluate the influences of moisture and temperature on the bifurcation load of cylindrical, composite panels subject to axial loading. The composite panels were 8-ply graphite/epoxy (AS/3501-5) laminates. The laminate ply orientations considered were (0., 45., -45., 90.) S, (90., 45., -45., 0.) S, and (45., -45.) 2S. The analysis included several different panel radii, two sets of boundary conditions, and three sets of initial moisture conditions. To evaluate the influences of moisture and temperature, the transverse moduli, E2, and shear moduli, G12, were degraded based on test data for the AS/3501-5 system. Each ply orientation was evaluated at 20 time/temperature conditions that ranged from 80 F to 300 F and moisture concentrations ranging from zero moisture content to an equilibrium moisture concentration distribution. The bifurcation loads were determined using the STAGS-C1 finite element shell analysis program. The bifurcation analysis mode with a pre-buckled linear displacement option was used for the analysis. Moisture and temperature were found to cause a reduction in the panels' bifurcation load ranging from 20.6 percent for the (0., 45., -45., 90.)S laminate to 42.7 percent for the (45., -45.) 2S laminate. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1981
- Accession Number
- ADA111127
Entities
People
- James M. Snead
Organizations
- Air Force Institute of Technology