Investigations of the mechanical behavior of graphite/PEEK (APC-2) composites

Thesis/Dissertation · Mon Dec 31 23:00:00 EST 1990

OSTI ID:7038378

Lee, K

The purpose was to investigate the effects of two phenomena specific to thermoplastic resin composites. These phenomena are: (a) significant nonlinear creep, that occurs especially at high temperatures, which affects the residual thermal stresses in a geometrically constrained structure; and (b) spatially nonuniform transverse crystallinity that develops in some fiber-reinforced thermoplastic composites, which introduces spatial variability and nonlinearity in the stiffness of the composite. The first part is related to (a). It presents a computational scheme for the optimal temperature path for APC-2 composite laminate, modeled as nonlinear, thermorheologically complex, viscoelastic material. The laminate is assumed to be sufficiently thin to obviate accounting for temperature nonuniformities across the thickness. The second part concerns (b) and presents analytical/computational results for the in-plane stresses in a moderately thick, cross-ply, graphite/PEEK (APC-2) laminate accounting for effects of nonuniform PEEK crystallinity across the plate's thickness.

• Research Organization: Tennessee Univ., Knoxville, TN (United States)
• OSTI ID: 7038378
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
CARBON
COMPOSITE MATERIALS
CREEP
ELEMENTAL MINERALS
ELEMENTS
FIBERS
GRAPHITE
MATERIALS
MECHANICAL PROPERTIES
MINERALS
NONLINEAR PROBLEMS
NONMETALS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYMERS
STRESSES
SYNTHETIC MATERIALS
THERMAL STRESSES
THERMOPLASTICS