Design Of Honeycomb Structures Research Articles

Graded negative Poisson’s ratio honeycomb structure design and application

A sub-domain size optimization method is conducted to design degraded negative Poisson’s ratio honeycomb structures, which could fully utilize the material behavior, such as minimum weight, maximum...

A new design of cellular soft continuum manipulator based on beehive-inspired modular structure

In this article, a design of honeycomb structure–based soft continuum manipulator is proposed to achieve higher structural strength while keeping compact layout, low material consumption, and thinn...

Mechanical properties of additively manufactured octagonal honeycombs

Honeycomb structures have found numerous applications as structural and biomedical materials due to their favourable properties such as low weight, high stiffness, and porosity. Application of additive manufacturing and 3D printing techniques allows for manufacturing of honeycombs with arbitrary shape and wall thickness, opening the way for optimizing the mechanical and physical properties for specific applications. In this study, the mechanical properties of honeycomb structures with a new geometry, called octagonal honeycomb, were investigated using analytical, numerical, and experimental approaches. An additive manufacturing technique, namely fused deposition modelling, was used to fabricate the honeycomb from polylactic acid (PLA). The honeycombs structures were then mechanically tested under compression and the mechanical properties of the structures were determined. In addition, the Euler-Bernoulli and Timoshenko beam theories were used for deriving analytical relationships for elastic modulus, yield stress, Poisson's ratio, and buckling stress of this new design of honeycomb structures. Finite element models were also created to analyse the mechanical behaviour of the honeycombs computationally. The analytical solutions obtained using Timoshenko beam theory were close to computational results in terms of elastic modulus, Poisson's ratio and yield stress, especially for relative densities smaller than 25%. The analytical solutions based on the Timoshenko analytical solution and the computational results were in good agreement with experimental observations. Finally, the elastic properties of the proposed honeycomb structure were compared to those of other honeycomb structures such as square, triangular, hexagonal, mixed, diamond, and Kagome. The octagonal honeycomb showed yield stress and elastic modulus values very close to those of regular hexagonal honeycombs and lower than the other considered honeycombs.

Honeycomb Structure Design Based on Finite Element Method

The element model of a honeycomb structure is established by using ANSYS software. Then theinfluence of design parameters such as inscribed circle diameter and thicknessof honeycomb on the strength and stiffness of honeycomb structure is explored.Under a given external load condition, the honeycomb structure which satisfies the equivalent stress criteria is got by changing inscribed circle diameter,wall thickness and skin thickness of a standard structure respectively. Comparethe weight of honeycomb structure get from these three methods and generalize a method of honeycomb structure lightweight design which satisfies different requirements.

Bioinspired Design of Honeycomb Structure Interfaces with Controllable Water Adhesion

Inspired by biological attachment systems, we fabricated the honeycomb structural films with different diameters by breath figure (BF) method, which were similar to the patterned octopus suckers. The experimental results showed, besides different van der Waals forces between the polystyrene (PS) surfaces and water, another important factor; that is, different negative pressures produced by different volumes of sealed air could be a crucial factor for the different adhesions. So the water adhesive forces of the as-prepared films can be effectively controlled from relative high to relative low adhesion by varying the pore diameters, which effectively adjusted the negative pressures produced by the pores. This unique adhesive phenomenon of honeycomb structure will be very useful for manipulating water droplet behaviors, as well as controlling liquid collection and transportation. These findings are interesting and helpful for us to further understand the biological attachment systems and to optimize the design of artificial analogues.

Surface enhanced Raman scattering substrate based on gold-coated anodic porous alumina template

We report the fabrication of large area SERS substrates based on anodic porous alumina template over which gold thin layer of 25 nm was deposited. A specific design of honey-comb structure with the pore size/cell thickness of 60/40 nm was attained by using the controlled electrolyte potential, time of etching and oxalic acid as an electrolytic solution. Cresyl violet and glycine molecules were deposited through chemisorption technique to verify the SERS substrate functionality. Numerical simulations in order to describe the realistic device were also carried out, finding consistency with the experimental results.

Selective Laser Melting of Honeycombs with Negative Poisson’s Ratio

Laser Freeform Fabrication allows additive manufacturing of functional parts from metallic powder materials. This yields potential for product innovations due to increased geometric degrees of freedom. Additional advantages are reduction of throughput time and economical manufacturing of small lot sizes. Hence, these processes are capable of producing structures of complex freeform geometry that cannot be manufactured at all with conventional processes [1]. This provides the possibility to manufacture designs that show a negative Poisson’s ratio ν. It gives the relation of the negative transverse strain to the longitudinal strain of a material exposed to uniaxial tension or compression. The longitudinal strain occurs in the load direction, whereas the transverse strain is found normal to this axis. Typically, the Poisson’s ratio is greater than zero, i.e. in tension a material’s volume can increase or remain constant while the behaviour in compression is vice versa. However, some materials can exhibit negative values between –1 and 0 meaning that they show unexpected behaviour by expanding transversely under tensile forces and vice versa under compression. This circumstance can be exploited in applications where parts are subject to compressive deformation but which are not allowed to expand laterally in order to not cause damage in adjacent components. Examples are crash impact absorbers and artificial intervertebral discs, etc. Experimental results were obtained from new honeycomb structures that were manufactured with Selective Laser Melting from stainless steel powder and tested in a universal testing machine under elastic, compressive deformation. Thus rules for successful design of honeycomb structures with negative Poisson’s ratio were derived.