Abstract: Three-Dimensional(3D) printing, also termed as Additive Manufacturing (AM), has experienced significant development in the last several years. This advanced technology has the potential to promote new revolution in high-end equipment manufacturing, and has been widely used in aerospace, marine, electronic and biomedical engineering. Fiber reinforced composites can offer significant advantages over metals, for their excellent mechanical properties, weight saving potential, good resistance to corrosion and fatigue, design tailorability, etc. AM of fiber-reinforced composites can promote AM into a robust manufacturing paradigm and make great possibility for customization, automatic fabrication and flexibility in designing high performance components with complicated geometries at relatively low cost and time. 3D printed continuous fiber-reinforced composites therefore have got great attention in the last several years. This paper provides a critical review on the mechanical properties and performance of 3D printed continuous fiber-reinforced composites. Specifically, a thorough discussion on the effects of printing process parameters on the performance of 3D printed composites has been carefully provided in the first part of this paper. The mechanical properties and damage mechanisms of 3D printed composites under various loading conditions are subsequently discussed and summarized. The corresponding models and methods for stiffness and strength prediction of 3D printed composites are introduced in the third part. Future research directions and desirable objectives are also discussed.

Key words: 3D printing, continuous fiber-reinforced composite, process parameter, mechanical property, damage mechanism