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Showing 1 to 20 of 24 for “"Auxetic"”.
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A new class of auxetic lattices
… and thermal behavior of a new class of auxetic lattices. We have started introducing a novel two-dimensional lattice family with three different realizations that leads to a Poisson's ratio arbitrarily close to the thermodynamic limit corresponding to ν = -1. The effect is achieved by …
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Isogeometric topology optimization for auxetic metamaterials and structures
… also applied to implement the rational design of auxetic metamaterials and auxetic composites. In Chapter 1, we provide a brief description for the main intention of the current work. In Chapter 2, the comprehensive review about the developments of topology optimization, isogeometric topology …
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Bistable Auxetic System -- Programming synclastic curvature into 2D Patterning
… inspiration from the transformation process of auxetic materials and embeds this within a bi-stable mechanism. Starting from fundamental geometric research of linear hinges and out-of-plane rotation, geometrical constraints are identified thoroughly for the length-preserving transformation …
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Crack growth, singularities and wave propagation in auxetic composite materials
An auxetic material is a material which has a negative Poisson's ratio, so they exhibit lateral expansion upon longitudinal tensile loading, or undergo lateral contraction under longitudinal compression. Such materials can exist in cellular form, or along specific axes in certain crystals. The …
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Experimental and Numerical Study of Ductile Metal Auxetic Tubular Structures
… structures are of high interest to researchers. Auxetic structures are a new class of metamaterials that exhibit counterintuitive negative Poisson's ratio (NPR) behavior based on their geometric configuration. Cellular auxetics are light-weight and cost-effective materials that have the potential …
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Additively manufactured aluminium auxetic architecture with targeted mechanical and energy absorption characteristics
Auxetic materials offer unconventional properties owing to their negative Poisson’s ratio (−𝜐) leading to deformation modes and mechanical characteristics different to traditional porous architecture. This leads to favourable outcomes for lightweight applications where precise control of the …
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Additive manufacturing of stiffness optimised auxetic bone scaffold using cobalt-chromium-molybdenum superalloy
Auxetic materials offer unconventional strain behaviour owing to their negative Poisson’s ratio (−𝜐) leading to deformation modes and mechanical characteristics different to traditional porous architecture. This can lead to favourable outcomes for load-bearing tissue engineering constructs, such as …
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CHARACTERIZATION AND MODELLING OF MAGNETO-AUXETICITY, THE MAGNETICALLY INDUCED AUXETIC BEHAVIOR, IN GALFENOL
… when elongated and narrower when compressed (aka auxeticity). This is an anisotropic, in-plane and volume conserving phenomenon with compensating contractions and expansions in the third (out of plane) direction. Since there is good magneto-elastic coupling in Galfenol, a negative Poisson’s ratio …
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Design, production and evaluation of an auxetic straining device for application in lung tissue engineering scaffolds
… on the negative Poisson’s ratio exhibited by auxetic materials, it was possible to translate uniaxial loading into biaxial expansion. Poly-L-lactide and polypropylene re-entrant honeycomb auxetic meshes were 3D-printed and incorporated into collagen scaffolds. Computational simulations were …
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Re-addressing the role of knitted textile design knowledge: auxetic textiles from a practice-led, designer-maker perspective
… methodology, which is used to produce auxetic, weft-knitted textiles. By using a designer-maker’s practice-led perspective to create functional fabrics, it seeks to challenge the perception that technical and functional research in textiles is or should be the domain of scientific …
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A Multi-Material Projection Stereolithography System for Manufacturing Programmable Negative Poissons Ratio Structures
… are realized. Researchers have been studying auxetic structures over decades, the mechanical property control of auxetic structure mainly relies on geometry design in previous studies. Now with the help of EMSL system, other design variables associated with auxetic structures, such as material …
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Design and optimization of lattice structures and mechanical metamaterials for additive manufacturing
… properties, such as programmable permeability, auxetic response, and dual-stiffness characteristics. Various AM processes, including Digital Light Processing (DLP), Fused Deposition Modelling (FDM), and Selective Laser Sintering (SLS), are employed for the fabrication of the designed lattice …
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Printing ferromagnetic domains in soft materials : mechanism, modeling, and applications
… of transformation such as remotely controlled 3D auxetic behaviors in an extremely fast and fully reversible manner via magnetic actuation. The actuation speed and power density of the printed soft materials with programmed ferromagnetic domains are orders of magnitude greater than existing …
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Experimental Testing and Numerical Investigation of Materials with Embedded Systems during Indentation and Complex Loading Conditions
… systems in a half space. The influence of auxeticity on the indentation stiffness ratio and the de-formation of the embedded system under different conditions (indenter size, thickness and embedment depth of the embedded layer) was established and key mechanisms of the Poisson’s ratio …
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Modeling and simulation of stochastic phenomena in carbon nanotube-based single molecule sensors
… lead to a negative Poisson's ratio, known as an auxetic material. We present simulations for what the properties of a sheet might look like. In addition, we present simulations for how these properties change as a membrane is strained and showing the conditions over which these surfaces have …
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A high-deformation electric soft robotic gripper via handed shearing auxetics
… robotic actuators built from handed shearing auxetics (HSAs). Soft robots - robots made out of more compliant materials such as rubber and silicone - are significantly more robust and safer than their rigid-bodied counterparts due to their intrinsic compliance. However, existing soft robots …
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Influence of geometric parameters on 3D periodic lattice effective properties
… isotropic, and tetragonal symmetry, including an auxetic geometry, over a wide range of relative densities are analyzed within a finite element framework. The effect of geometric parameters on lattice properties is discussed and a comparison between lattices based on their anisotropy index is …
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Ex Vivo Deformations of the Uterosacral Ligaments
… direction, revealing that the USLs may behave as auxetic structures. The fourth and final chapter presents preliminary findings on novel imaging applications to characterize the evolving structure of the USLs before, during, and after tensile pulling along the ligaments' main textit{in vivo} axis …
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Large Strain Finite Element Analysis of Spinodal Shell Structures
… layer, but the simulations showed only localized auxetic behavior in the middle of the structures. Strain localization was observed in the gradient structures, as the changing anisotropy encouraged strain to localize to each layer, but this strain did not cause localized failure. The stress state …
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Additively Manufactured Metallic Cellular Materials for Blast and Impact Mitigation
… honeycomb hybridised with lattice walls, and an auxetic stacked-origami geometry, manufactured and tested experimentally here for the first time. It is shown that the hybrid lattice-honeycomb geometry outperformed the benchmark metallic square honeycomb in terms of energy absorption efficiency in …
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