scholarly journals Regularly configured structures with polygonal prisms for three-dimensional auxetic behaviour

2017 ◽  
Vol 473 (2202) ◽  
pp. 20160926 ◽  
Author(s):  
Junhyun Kim ◽  
Dongheok Shin ◽  
Do-Sik Yoo ◽  
Kyoungsik Kim
Keyword(s):  
Poisson’S Ratio ◽  
Three Dimensional ◽  
Unit Cell ◽  
Poisson's Ratio ◽  
Numerical Verification ◽  
Geometric Conditions ◽  
Unit Cells ◽  
Negative Poisson's Ratio ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

We report here structures, constructed with regular polygonal prisms, that exhibit negative Poisson’s ratios. In particular, we show how we can construct such a structure with regular n -gonal prism-shaped unit cells that are again built with regular n -gonal component prisms. First, we show that the only three possible values for n are 3, 4 and 6 and then discuss how we construct the unit cell again with regular n -gonal component prisms. Then, we derive Poisson’s ratio formula for each of the three structures and show, by analysis and numerical verification, that the structures possess negative Poisson’s ratio under certain geometric conditions.

scholarly journals Giant negative Poisson’s ratio in two-dimensional V-shaped materials

2021 ◽  
Author(s):  
Xikui Ma ◽  
Jian Liu ◽  
Yingcai Fan ◽  
Weifeng Li ◽  
Jifan Hu ◽  
...  
Keyword(s):  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Negative Poisson’S Ratio ◽  
Two Dimensional ◽  
Auxetic Materials ◽  
Negative Poisson's Ratio ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

Two-dimensional (2D) auxetic materials with exceptional negative Poisson’s ratios (NPR) are drawing increasing interest due to the potentials in medicine, fasteners, tougher composites and many other applications. Improving the auxetic...

scholarly journals The Multidirectional Auxeticity and Negative Linear Compressibility of a 3D Mechanical Metamaterial

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2193 ◽  
Author(s):  
Krzysztof K. Dudek ◽  
Daphne Attard ◽  
Ruben Gatt ◽  
James N. Grima-Cornish ◽  
Joseph N. Grima
Keyword(s):  
Theoretical Model ◽  
Poisson’S Ratio ◽  
Three Dimensional ◽  
Poisson's Ratio ◽  
Negative Poisson’S Ratio ◽  
Structural Units ◽  
Loading Direction ◽  
Arbitrary Loading ◽  
Negative Poisson's Ratio ◽  
Linear Compressibility

In this work, through the use of a theoretical model, we analyse the potential of a specific three-dimensional mechanical metamaterial composed of arrowhead-like structural units to exhibit a negative Poisson’s ratio for an arbitrary loading direction. Said analysis allows us to assess its suitability for use in applications where materials must be able to respond in a desired manner to a stimulus applied in multiple directions. As a result of our studies, we show that the analysed system is capable of exhibiting auxetic behaviour for a broad range of loading directions, with isotropic behaviour being shown in some planes. In addition to that, we show that there are also certain loading directions in which the system manifests negative linear compressibility. This enhances its versatility and suitability for a number of applications where materials exhibiting auxetic behaviour or negative linear compressibility are normally implemented.

Three-dimensional porous borocarbonitride BC2N with negative Poisson's ratio

2020 ◽  
Vol 8 (44) ◽  
pp. 15771-15777
Author(s):  
Kashif Hussain ◽  
Umer Younis ◽  
Imran Muhammad ◽  
Yu Qie ◽  
Yaguang Guo ◽  
...  
Keyword(s):  
Poisson’S Ratio ◽  
Three Dimensional ◽  
Poisson's Ratio ◽  
Negative Poisson’S Ratio ◽  
Negative Poisson's Ratio ◽  
Recent Synthesis

Motivated by the recent synthesis of three-dimensional (3D) porous borocarbonitride (Angew. Chem., Int. Ed., 2019, 58, 6033–6037), we propose a porous 3D-BC2N structure composed of BC2N nanoribbons.

Kinematics of the Morph Origami Pattern and its Hybrid States

2020 ◽  
Author(s):  
Phanisri P. Pratapa ◽  
Ke Liu ◽  
Glaucio H. Paulino
Keyword(s):  
Configuration Space ◽  
Poisson’S Ratio ◽  
Plane Deformation ◽  
Mode Locking ◽  
Unit Cell ◽  
Poisson's Ratio ◽  
Form Complex ◽  
Mountain Valley ◽  
Characteristic Modes ◽  
Unit Cells

Abstract A new degree-four vertex origami, called the Morph pattern, has been recently proposed by the authors (Pratapa, Liu, Paulino, Phy. Rev. Lett. 2019), which exhibits interesting properties such as extreme tunability of Poisson’s ratio from negative infinity to positive infinity, and an ability to transform into hybrid states through rigid origami kinematics. We look at the geometry of the Morph unit cell that can exist in two characteristic modes differing in the mountain/valley assignment of the degree-four vertex and then assemble the unit cells to form complex tessellations that are inter-transformable and exhibit contrasting properties. We present alternative and detailed descriptions to (i) understand how the Morph pattern can smoothly transform across all its configuration states, (ii) characterize the configuration space of the Morph pattern with distinguishing paths for different sets of hybrid states, and (iii) derive the condition for Poisson’s ratio switching and explain the mode-locking phenomenon in the Morph pattern when subjected to in-plane deformation as a result of the inter-play between local and global kinematics.

scholarly journals Non-Auxetic Mechanical Metamaterials

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 635 ◽  
Author(s):  
Christa de Jonge ◽  
Helena Kolken ◽  
Amir Zadpoor
Keyword(s):  
Mechanical Properties ◽  
Yield Stress ◽  
Fatigue Behavior ◽  
Analytical Data ◽  
Three Dimensional ◽  
Mechanical Metamaterials ◽  
Macro Scale ◽  
Unit Cells ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

The concept of “mechanical metamaterials” has become increasingly popular, since their macro-scale characteristics can be designed to exhibit unusual combinations of mechanical properties on the micro-scale. The advances in additive manufacturing (AM, three-dimensional printing) techniques have boosted the fabrication of these mechanical metamaterials by facilitating a precise control over their micro-architecture. Although mechanical metamaterials with negative Poisson’s ratios (i.e., auxetic metamaterials) have received much attention before and have been reviewed multiple times, no comparable review exists for architected materials with positive Poisson’s ratios. Therefore, this review will focus on the topology-property relationships of non-auxetic mechanical metamaterials in general and five topological designs in particular. These include the designs based on the diamond, cube, truncated cube, rhombic dodecahedron, and the truncated cuboctahedron unit cells. We reviewed the mechanical properties and fatigue behavior of these architected materials, while considering the effects of other factors such as those of the AM process. In addition, we systematically analyzed the experimental, computational, and analytical data and solutions available in the literature for the titanium alloy Ti-6Al-4V. Compression dominated lattices, such as the (truncated) cube, showed the highest mechanical properties. All of the proposed unit cells showed a normalized fatigue strength below that of solid titanium (i.e., 40% of the yield stress), in the range of 12–36% of their yield stress. The unit cells discussed in this review could potentially be applied in bone-mimicking porous structures.

Multilayer Composite Materials with Non-Usual Poisson's Ratios

2007 ◽  
Vol 555 ◽  
pp. 545-552 ◽  
Author(s):  
E.H. Harkati ◽  
Z. Azari ◽  
P. Jodin ◽  
A. Bezazi
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Poisson’S Ratio ◽  
Cellular Materials ◽  
Poisson's Ratio ◽  
Multilayer Composite ◽  
Computer Programme ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

Most of usual materials exhibit Poisson's ratio comprised between 0 and 0.5. But, for some kind of cellular materials, or for some stacking sequences of unidirectional plies, a composite material can exhibit negative or greater than 0.5 Poisson's ratios. In this paper, a study of different stacking sequences such as [±β/±θ]s plies made from highly anisotropic fibre pre-preg is presented. A special computer programme has been developed for this purpose. Eighteen stacking sequences, including the [±θ] ones, have been computed. The results show that at least one of Poisson's ratios varies between -0.8 to +0.4. Such kind of materials may find applications for particular cases, as their strength is significantly increased by this phenomenon.

Multi-objective optimization of a novel crash box with a three-dimensional negative Poisson’s ratio inner core

2017 ◽  
Vol 233 (2) ◽  
pp. 263-275 ◽  
Author(s):  
ChunYan Wang ◽  
SongChun Zou ◽  
WanZhong Zhao
Keyword(s):  
Energy Absorption ◽  
Optimization Algorithm ◽  
Poisson’S Ratio ◽  
Inner Core ◽  
Three Dimensional ◽  
Poisson's Ratio ◽  
Negative Poisson’S Ratio ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Negative Poisson's Ratio

The crash box can absorb energy from the beam as much as possible, so as to reduce the collision damage to the front part of the car body and protect the safety of passengers. This work proposes a novel crash box filled with a three-dimensional negative Poisson’s ratio (NPR) inner core based on an inner hexagonal cellular structure. In order to optimize and improve the crash box’s energy absorption performance, the multi-objective optimization model of the NPR crash box is established, which combines the optimal Latin hypercube design method and response surface methodology. Then, the microstructure parameters are further optimized by the multi-objective particle swarm optimization algorithm to obtain an excellent energy absorption effect. The simulation results show that the proposed NPR crash box can generate smooth and controllable deformation to absorb the total energy, and it can further enhance the crashworthiness through the designed optimization algorithm.

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