Comparisons of the Performance of Novel Lightweight Three-Dimensional Hybrid Composites against GLARE Fiber-Metal Laminate

The objective of the work presented in this paper is to overcome several major shortcomings of the recently introduced 3D composites (3DCs) and their fiber-metal-laminate renditions (3DFMLs). A new class of lightweight, stiff, and resilient three-dimensional hybrid composites (3DHCs) is introduced in this study, referred to as "inserts enhanced 3D hybrid composites" (IE3DHCs). The performances of all configurations were characterised by conducting three-point flexural tests using a span-to-thickness ratio of 32:1. The flexural performance of 3DFMLs with different core thicknesses was first compared using GLARE-3/2-0.4 as a baseline, revealing the superior performance of 3DFMLs; the optimal performance was exhibited by 3DFML with a 3 mm 3DC core. However, the lower ductility of 3DFMLs, as well as their poorly controlled and time-consuming fabrication process were recognized. The newly developed materials (IE3DHCs) had a comparatively simpler fabrication processes with significantly higher quality control. More importantly, IE3DHCs exhibited an approximately 160% improvement in ductility and as much as a 250% improved design strength compared to 3DFMLs. These findings showcase the promising potential of IE3DHCs for future research and real-world applications. Additionally, robust finite element models were developed to simulate flexural tests and optimize future renditions of the IE3DHCs.