Mechanical response of Ti–6Al–4V octet-truss lattice structures

A series of experimental investigations and numerical analyses is presented into the compression response, and subsequent failure modes in corrugated-core sandwich panels based on an aluminium alloy, a glass fibre reinforced plastic (GFRP) and a carbon fibre reinforced plastic (CFRP). The corrugated-cores were fabricated using a hot press moulding technique and then bonded to face sheets based on the same material, to produce a range of lightweight sandwich panels. The role of the number of unit cells and the thickness of the cell walls in determining the overall deformation and local collapse behaviour of the panels is investigated. The experiments also provide an insight into the post-failure response of the sandwich panels. The results are compared with the numerical predictions offered by a finite element analysis (FEA) as well as those associated with an analytical model. Buckling of the cell walls has been found to be initial failure mode in these corrugated systems. Continued loading resulted in fracture of the cell walls, localised delamination as well as debonding between the skins and the core. The predictions of the FEA generally show reasonably good agreement with the experimental measurements. Finally, the specific compressive properties of the corrugated structures have been compared to those of other core materials where evidence suggests that these systems compare favourably with their more conventional counterparts.

The Mechanical Behaviour of Corrugated-Core Sandwich Panels

Mechanical behavior of the sandwich structures with carbon fiber-reinforced pyramidal lattice truss core

Energy absorption and low velocity impact response of polyurethane foam filled pyramidal lattice core sandwich panels

Wire-woven bulk Kagome truss cores

Mechanical behavior of sandwich panels with tetrahedral and Kagome truss cores fabricated from wires

The authors have noted that wires could be the best candidate material to create truss PCMs, because they can easily obtain high strength as in piano wires, are simple to be fabricated, and can be controlled for good quality. Seven new ideas to fabricate truss PCMs using wires, namely, straight bulk octet, bulk woven Kagome, circular spring Kagome, hexagonal spring Kagome, dual wired octet, and dual wired Kagomes are presented. The assembly process, the geometry, features and benefit of each idea are described. Also, the analytic solutions of the stiffness or strength, and the constraints for selecting proper materials are discussed.

Wire Formed Cellular Metals

Compressive and Bending Behavior of Sandwich Panels with Octet Truss Core Fabricated from Wires

Many studies have been focused on how to manufacture ultra light metal structures and optimize them. In this study, we introduced a new idea to make sandwich panels with quasi-Kagome truss cores. First, metal sheets with a peculiar pattern of slits were expanded to be meshes, they are crimped into a triangular wave pattern, and then one third of struts were bent reversely to be quasi-Kagome trusses. Finally, two face sheets were bonded on the upper and the lower sides. The bending strength was estimated through elementary mechanics for the sandwich specimens with two kinds of face sheet the results of estimation were compared with the those of finite element analyses and experiments.

https://www.koreascience.kr:443/article/JAKO200634741562367.pdf

Ji-Hyun Lim

Papers

Mechanical behavior of sandwich panels with tetrahedral and Kagome truss cores fabricated from wires

Wire Formed Cellular Metals

Compressive and Bending Behavior of Sandwich Panels with Octet Truss Core Fabricated from Wires

Mechanical Behavior of Sandwich Panels with Quasi-Kagome Truss Core Fabricated from Expanded Metals