Effect of adhesive layers on impact damage and dynamic response in composite laminates

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5287865

Rechak, S

Adhesive layers were included along the interfaces of a base-line graphite/epoxy (0/sub 5//90/sub 5//0/sub 5/) laminate for impact study. Impacted specimens were sectioned longitudinally and transversely for observation of the damage modes. The presence of adhesive layers resulted in the following effects: (1) Delamination was effectively suppressed up to very-high-impact velocities. (2) Matrix cracking in the upper lamina was greatly reduced. (3) The contact area was appreciably increased, thus the stress concentration effect significantly reduced. One major disadvantage in using adhesive layers was found: the bending crack in the bottom lamina, which could branch out into delamination when adhesive layers were absent, tended to penetrate in the middle lamina and break fibers. It is suggested that the use of adhesive strips along the bottom interface would prevent the bending crack from penetrating into adjacent lamina. A simple experimental technique was proposed for crack-propagation studies. Calculated crack-propagation speed was about 45% the wave speed of graphite/epoxy, in the case of cross ply adhesive, and about 30% the wave speed velocity of graphite/epoxy, for the case of (0/sub 5//90/sub 5/0/sub 5/) composite laminate.

• Research Organization: Purdue Univ., Lafayette, IN (USA)
• OSTI ID: 5287865
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ADHESIVES
CARBON
COMPOSITE MATERIALS
CRACKS
DAMAGE
ELEMENTAL MINERALS
ELEMENTS
EPOXIDES
FUNCTIONS
GRAPHITE
IMPACT TESTS
INTERFACES
LAYERS
MATERIALS
MATERIALS TESTING
MATRIX MATERIALS
MECHANICAL TESTS
MINERALS
NONMETALS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
RESPONSE FUNCTIONS
TESTING