State-Of-The-Art of Sandwich Composite Structures: Manufacturing—to—High Performance Applications

TLDR

Sandwich composite structures combine lightweight, high strength, impact resistance, and stability, and are employed in aerospace, marine, construction, automotive, and energy‑absorption applications using core materials such as cellular polymer foam, metallic foam, honeycomb, balsa, and tubular geometries. This review investigates the fundamentals, design, manufacturing, machining, and future challenges of sandwich composites. The authors describe manufacturing techniques—including hand lay‑up, press, prepreg, vacuum bagging/autoclave, resin transfer molding, compression molding, pultrusion, 3D and 4D printing—as well as machining processes for these composites.

Abstract

This cutting-edge review highlights the fundamentals, design, and manufacturing strategies used for sandwich composites. Sandwich composite structures have the advantages of light weight, high strength, impact resistance, stability, and other superior features for advanced applications. In this regard, different core materials have been used in the sandwich composite structures, such as cellular polymer foam, metallic foam, honeycomb, balsa, tubular, and other core geometries. Among these, honeycomb sandwich composite materials have been effectively applied in space engineering, marine engineering, and construction applications. The foremost manufacturing techniques used for sandwiched composite structures include hand lay-up, press method, prepreg method, vacuum bagging/autoclave, vacuum assisted resin infusion, resin transfer molding, compression molding, pultrusion, three-dimensional (3D) printing, four-dimensional (4D) printing, etc. In advanced composite manufacturing, autoclave processes have been the method of choice for the aerospace industry due to less delamination between plies and easy control of thickness dimensions. Moreover, machining processes used for sandwich composites are discussed in this article. In addition to aerospace, the high-performance significance of sandwiched composite structures is covered mainly in relation to automobile engineering and energy absorption applications. The structure-, fabrication-, and application-related challenges and probable future research directions are also discussed in this article.