An overview of the formation of fibre waviness and its effect on the mechanical performance of fibre reinforced polymer composites

Lightweight primary and secondary structures of aircraft, wind turbines and automobile are mostly made of polymer-matrix composites. The selection of fibre reinforced polymer (FRP) composites for the primary structure is performance-based assuming defect-free components, especially in the aerospace industry. However, for the usage of FRP composites for secondary structures, the effect of manufacturing induced defects can be tolerated for cost-effective manufacturing. Fibre waviness has a major influence on the mechanical performance of composites and its study is one of the major concerns. The present work deals with an overview of the earlier reported studies on the effect of fibre waviness, and its formation, on the elastic properties and mechanical response of the FRP composites. Accumulation and discussion of results of the existing literature over the past two decades are summarized together up to the current status in the field. Capabilities of different non-destructive techniques used for characterisation of fibre waviness defect are summarized.