Analysis of the Bearing Stress Caused by the Impact of Mechanical Fasteners on Quasi-Isotropic CFRP Composite

Angelika ARKUSZYŃSKA; Angelika ARKUSZYŃSKA

Download

This publication is protected and available only for logged users.

Title: Analysis of the Bearing Stress Caused by the Impact of Mechanical Fasteners on Quasi-Isotropic CFRP Composite

Abstract:

This research aimed to determine the bearing strength of quasi-isotropic composites, considering their application in aircraft airframe repairs, and to investigate the influence of joint geometry on this strength. The research focused on a CFRP composite produced from a carbon prepreg. Specimens cut from the composite underwent static tensile testing to determine their tensile strength and modulus of elasticity. The effect of drilling a hole for a mechanical fastener on the composite material’s strength was examined. The influence of the hole’s distance from the specimen edge on the bearing stress and the maximum failure loads was investigated. The surface bearing stress in the composite under bolt load was determined, and tomographic tests were performed. Experimental studies were supplemented by numerical analysis, yielding stress distributions within the composite under fastener load. It was demonstrated that the failure load increases as the hole’s distance from the specimen edge increases. Furthermore, the reduction in composite material strength due to drilling was estimated at approximately 30%. The results highlight the importance of considering this strength reduction and maintaining appropriate rivet or bolt joint dimensions during the design of mechanical joints in composites.