The influence of stress ratio and temperature on the fatigue crack growth rate behavior of ARALL

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Journal of Composites Technology and Research; (United States)

OSTI ID:6048856

Salivar, G C; Gardini, C A ^[1]

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1. Florida Atlantic Univ., Boca Raton (United States) Pratt Whitney Group, West Palm Beach, FL (United States)

The fatigue crack growth rate behavior of ARALL (aramid-reinforced aluminum laminate) was investigated as a function of stress ratio and temperature. The particular material was ARALL-3, a 7475-T76 aluminum alloy laminate. Tests were conducted for stress ratios of 0.1 and 0.5 at temperatures of 21, 82, and 93 C (70, 180, and 200 F) using a center-cracked panel geometry (measurements were made in English units and converted to SI units). The objective was to examine the contributions of the effects of crack closure and fiber bridging of the crack on the material behavior. Crack closure was monitored throughout the tests using compliance measurements. Fractography was used to investigate the influence of temperature on the integrity of the aluminum to epoxy/fiber bond to try to identify the effects of fiber bridging. Some crack closure, in the traditional metallic material sense, was evident through compliance measurements. However, the crack tip bridging by the fibers appears to be the dominant mechanism influencing the fatigue crack growth rate behavior in this material under these test conditions. Fractography indicates a considerable difference in fiber-bridging behavior between the room temperature and the elevated temperature tests. 19 refs.

• OSTI ID: 6048856
• Journal Information: Journal of Composites Technology and Research; (United States), Journal Name: Journal of Composites Technology and Research; (United States) Vol. 15:1; ISSN JCTRER; ISSN 0885-6804
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ARAMIDS
CRACK PROPAGATION
CRACKS
ELECTRON MICROSCOPY
FATIGUE
FRACTOGRAPHY
FRACTURE MECHANICS
MATERIALS
MATRIX MATERIALS
MECHANICAL PROPERTIES
MECHANICS
MICROSCOPY
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
SCANNING ELECTRON MICROSCOPY
STRESS ANALYSIS
SYNTHETIC MATERIALS
TEMPERATURE DEPENDENCE