Fatigue life enhancement of fibre-reinforced composites: A state-of-the-art review and outlook

Fibre-reinforced composites (FRCs) are widely used due to their outstanding mechanical properties; however, their vulnerability to fatigue failure remains a critical limitation, as multiple crack initiation sites can lead to progressive damage accumulation and ultimately undermine their long-term structural integrity. Despite extensive research on static and impact performance, fatigue degradation continues to pose a major barrier to their broader structural applications. Fatigue degradation in FRCs is governed by a complex interplay of primary and secondary factors, including reinforcement architecture, polymer matrix properties, fibre volume fraction, loading conditions, and environmental influences. The current state-of-the-art review presented herein highlights that incorporating fillers can significantly enhance fatigue performance; however, there remains a paucity of studies on the fatigue behaviour of FRCs modified with hybrid fillers. Accordingly, the objective of this review is to consolidate current knowledge on the fatigue performance of filler-modified FRCs, with particular emphasis on the role of single and hybrid nano-fillers, associated damage mechanisms, and the key challenges in fatigue life prediction. Finally, the review outlines the key challenges and future trends in filler-modified FRCs for advancing their practical implementation. Overall, this review provides a comprehensive framework to identify optimisation pathways for fatigue life enhancement, offering valuable guidance for designing next-generation FRCs with improved durability and reliability in cyclic loading applications.