Understanding Fatigue Damage Progression in Low Velocity Impacted CFRP Laminates through Stiffness Measurements

Abstract:

Carbon fibre composites used in many safety-critical applications experience damage due to operating environment such as bird strike, hailstorm etc., In some cases, the damage is barely visible and its presence in the structure can cause accelerated damage leading to catastrophic failure. In this paper, the results of fatigue damage progression in woven CFRP laminate subjected to constant amplitude loading for un-impacted specimens as well as impacted specimens are presented. The stiffness of the specimens was periodically monitored during fatigue testing to arrive at the rate of damage progression. Special experiments were carried out under a programmed version of an equivalent fighter aircraft loading – FALSTAFF (Fighter Aircraft Loading Standard for Fatigue and Fracture) and it was observed that the damage progression is slower in case of spectrum loading compared to constant amplitude loading. The effect of load sequencing on damage is investigated in this paper.

• Periodical: Materials Science Forum (Volumes 830-831)
• Pages: 413-416
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.830-831.413
• Online since: September 2015
• Authors: Raghu V. Prakash*, Deepika Sudevan
• Keywords: CFRP Laminate, FALSTAFF, Post-Impact Fatigue, Stiffness Degradation

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