Impact response and microstructural analysis of two glass/epoxy composite laminates

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:175415

Pang, S S; Krishnappa, S; Yang, C ^[1]

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1. Louisiana State Univ., Baton Rouge, LA (United States)

Low velocity impact tests were performed on two glass/epoxy (spring orientation and crossply) composite laminates. A weight drop tower tester was previously constructed to study the impact energy absorbed by composite pipe using various impactors. In addition, this tester was used to predict the contact duration, force indentation and displacement of laminated composites due to impact with a hemispherical impactor. Both of these studies primarily focus on the contact force of an impactor and on the response of the samples without consideration of the microscopic damage. In the current paper, the effect of impactor mass, two boundary conditions (clamp-free and clamped-clamped) and specimen dimension (length) on the impact response and microstructural damage were studied using the same experimental device. The resulting damaged specimens were sectioned and observed in an optical microscope. The energy levels in the two laminates were of similar magnitude but the delamination pattern and microstructural damage modes were quite different. The energy absorbed, peak force, and contact time increased with the increase in the impactor mass. The energy absorbed by similar specimens for the two boundary conditions were of similar magnitude, but the microstructural damage was different. The energy absorbed and the contact time increased with the increase in the specimen length. Conversely, the peak force and the visibility of the surface damage decreased with an increase in the specimen length. A correlation between the impact response and microstructural damage is provided. The observations are discussed in terms of rigidity of the specimen (support) and potential damage sites.

• OSTI ID: 175415
• Report Number(s): CONF-950686--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
BOUNDARY CONDITIONS
EPOXIDES
GLASS
IMPACT TESTS
MICROSTRUCTURE
ORIENTATION
VELOCITY