Failure mechanisms in NCF composite bolted joints: Experiments and FE model

Abstract

The current study focuses on the bearing failure process of NCF composites and associated damage mechanisms. A set of experiments on bolted joints between NCF composite and steel plates have been performed. The bearing damage onset and failure progression in the composite was monitored at different load levels by microscopic image analysis. Fibre kinking in 0° layers was found as the key damage mechanism that initiates and drive the bearing failure. Matrix cracking and delaminations were found as well. A cost-effective FE model that predicts bolt bearing failure of NCF composites was proposed. The model utilises state-of-the-art failure criteria and predicts both intra- and inter-laminar progressive damage. A good correlation between the predicted damage development process and experiments was observed both in terms of failure modes and load levels.