SEDL / STP / STP813-EB / STP31818S

Compression Fatigue Damage in Thick, Notched Graphite/Epoxy Laminates

Black, NF
Engineer, Northrop Corp., Aircraft Division, Hawthorne, CA

Stinchcomb, WW
Professor, Virginia Polytechnic Institute and State University, Blacksburg, VA

Pages: 21    Published: Jan 1983

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Abstract

This study has investigated the damage development mechanisms in notched graphite/epoxy composite laminates during constant-amplitude compressive fatigue loading. Laminates of two different stacking sequences were tested. The relationship between fatigue damage and the resulting life, stiffness, and strength of the laminates have been observed. X-ray radiography and ultrasonic C-scanning were used to characterize and monitor the damage that occurred during the fatigue loadings. Sectioning of the damaged laminates was performed to verify the extent of the observed damage in the X-ray radiographs and ultrasonic C-scans.

Damage in both laminate types consisted of matrix cracking and delaminations. The growth of the damage was observed to have a three-dimensional nature.