Multifunctional periodic cellular metals

Abstract

Periodic cellular metals with honeycomb and corrugated topologies are widely used for the cores of light weight sandwich panel structures. Honeycombs have closed cell pores and are well suited for thermal protection while also providing efficient load support. Corrugated core structures provide less efficient and highly anisotropic load support, but enable cross flow heat exchange opportunities because their pores are continuous in one direction. Recent advances in topology design and fabrication have led to the emergence of lattice truss structures with open cell structures. These three classes of periodic cellular metals can now be fabricated from a wide variety of structural alloys. Many topologies are found to provide adequate stiffness and strength for structural load support when configured as the cores of sandwich panels. Sandwich panels with core relative densities of 2-10% and cell sizes in the millimetre range are being assessed for use as multifunctional structures. The open, three-dimensional interconnected pore networks of lattice truss topologies provide opportunities for simultaneously supporting high stresses while also enabling cross flow heat exchange. These highly compressible structures also provide opportunities for the mitigation of high intensity dynamic loads created by impacts and shock waves in air or water. By filling the voids with polymers and hard ceramics, these structures have also been found to offer significant resistance to penetration by projectiles.

Reexamining the mechanical property space of three-dimensional lattice architectures

“…A large body of theoretical and experimental work has been dedicated to creating new lattice architectures and investigating their properties [1,15,18,19,23,[30][31][32][33][34]. Most analytical models for the mechanical behavior of both 2D and 3D lattices are derived using beam theory, and these models generally predict that strength and modulus follow a power law scaling with relative density as ‫ܧ‬ = ‫ܧܤ‬ ௦ ߩ̅ ,…”

Response of metallic pyramidal lattice core sandwich panels to high intensity impulsive loading in air

“…As the core relative density is decreased, the quasi-static strength of cores made from trusses begins to exceed that of the honeycomb webs because of their higher buckling resistance [21,22]. This has stimulated interest in the dynamic response of sandwich panel structures with lattice truss core topologies [23][24][25][26][27] even though they have limited stretch resistance [28][29][30].…”

Corrugated all-composite sandwich structures. Part 1: Modeling

“…During the past years, numerous core designs with improved quasi-static and dynamic performance have been proposed. These comprise aluminium foams [1,2] and various metallic core topologies such as truss-and plate-like configurations [3,4]. Numerous metallic truss configurations have been proposed with competitive quasi-static properties [5,6,7] and dynamic properties [8,9].…”