Fatigue/impact studies in laminated composites /
V. Sarma Avva.

Description

Main Author

Sarma Avva, V.

Related Names

Air Force Wright Aeronautical Laboratories
Air Force Flight Dynamics Laboratory (U.S.)
North Carolina Agricultural and Technical State University

Language(s)

English

Published

Wright-Patterson Air Force Base, Ohio : Flight Dynamics Laboratory, Air Force Wright Aeronautical Laboratories, Air Force Systems Command, United States Air Force, 1983.

Subjects

Materials > Materials / Fatigue.
Laminated materials.
Composite materials.
Epoxy compounds.
Graphite.
Composite materials.
Laminated materials.
Materials > Materials / Fatigue.

Summary

The residual strength of the impact-damaged laminates can be predicted using an analytical model. Both the power law and the wearout models appear to be useful in predicting the fatigue life of the composite laminates. However, because of the slope parameter, the wearout model appears to have a slight edge over the power law model, particularly at low fatigue life and higher applied stress. The strength degradation due to cyclic loading in notched laminates was found to be extremely small up to a million cycles. The residual strength of the fatigue-damaged laminates was found to increase (in proportion to the applied maximum stress with R = 0.1) after a million fatigue cycles. Impact loading followed by cyclic loading was found to be more damaging (in reducing the life of the laminate) than the reversed sequence of loading. The magnitude of the minimum projectile velocity causing catastrophic failure in the laminates tested was found as a function of the applied stress and the number of fatigue cycles.

Note

ADA142841.
"Final Report for Period 10 September 1980 to 31 December 1982."
"May 1983."

Physical Description

xiii, 139 pages : illustrations, tables ; 28 cm.

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