Geometrically nonlinear mechanical properties of auxetic double-V microstructures with negative Poisson's ratio

2020 ◽  
Vol 80 ◽  
pp. 103933 ◽  
Author(s):  
Qiang Gao ◽  
Chin An Tan ◽  
Greg Hulbert ◽  
Liangmo Wang
2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Kun Yuan ◽  
Meng-Yang Li ◽  
Yan-Zhi Liu ◽  
Ren-Zhong Li

The intrinsic negative Poisson’s ratio effect in 2-dimensional nanomaterials have attracted a lot of research interests due to its superior mechanical properties, and new mechanisms have emerged in the nanoscale. In this paper, we designed a novel graphyne-like two-dimensional carbon nanostructure with a “butterfly” shape (GL-2D-1) and its configuration isomer with a “herring-bone” form (GL-2D-2) by means of density functional theoretical calculation and predicted their in-plane negative Poisson’s ratio effect and other mechanical properties. Both GL-2D-1 and GL-2D-2 present a significant negative Poisson’s ratio effect under different specific strains conditions. By contrast, GL-2D-2 presents a much stronger negative Poisson’s ratio effect and mechanical stability than does GL-2D-1. It is hoped that this work could be a useful structural design strategy for the development of the 2D carbon nanostructure with the intrinsic negative Poisson’s ratio.


Author(s):  
Joseph N. Grima ◽  
Roberto Caruana-Gauci ◽  
Daphne Attard ◽  
Ruben Gatt

A three-dimensional cellular system that may be made to exhibit some very unusual but highly useful mechanical properties, including negative Poisson's ratio (auxetic), zero Poisson's ratio, negative linear and negative area compressibility, is proposed and discussed. It is shown that such behaviour is scale-independent and may be obtained from particular conformations of this highly versatile system. This model may be used to explain the auxetic behaviour in auxetic foams and in other related cellular systems; such materials are widely known for their superior performance in various practical applications. It may also be used as a blueprint for the design and manufacture of new man-made multifunctional systems, including auxetic and negative compressibility systems, which can be made to have tailor-made mechanical properties.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1353
Author(s):  
Chunxia Guo ◽  
Dong Zhao ◽  
Zhanli Liu ◽  
Qian Ding ◽  
Haoqiang Gao ◽  
...  

The synthesized understanding of the mechanical properties of negative Poisson’s ratio (NPR) convex–concave honeycomb tubes (CCHTs) under quasi-static and dynamic compression loads is of great significance for their multifunctional applications in mechanical, aerospace, aircraft, and biomedical fields. In this paper, the quasi-static and dynamic compression tests of three kinds of 3D-printed NPR convex–concave honeycomb tubes are carried out. The sinusoidal honeycomb wall with equal mass is used to replace the cell wall structure of the conventional square honeycomb tube (CSHT). The influence of geometric morphology on the elastic modulus, peak force, energy absorption, and damage mode of the tube was discussed. The experimental results show that the NPR, peak force, failure mode, and energy absorption of CCHTs can be adjusted by changing the geometric topology of the sinusoidal element. Through the reasonable design of NPR, compared with the equal mass CSHTs, CCHTs could have the comprehensive advantages of relatively high stiffness and strength, enhanced energy absorption, and damage resistance. The results of this paper are expected to be meaningful for the optimization design of tubular structures widely used in mechanical, aerospace, vehicle, biomedical engineering, etc.


2014 ◽  
Vol 1049-1050 ◽  
pp. 409-412 ◽  
Author(s):  
Zhou Xin ◽  
Wang Fan

Negative Poisson's ratio honeycomb structure has unique mechanical properties. It has very good prospects for development. A mechanical model of star-shaped honeycomb structure is proposed and the mechanical properties of the model are derived. It can provide theoretical reference for engineering design of this kind of new structure.


2021 ◽  
Vol 8 ◽  
Author(s):  
Di Gao ◽  
Bin Wang ◽  
Haoqiang Gao ◽  
Fuguang Ren ◽  
Chunxia Guo ◽  
...  

As a kind of metamaterial, the negative Poisson’s ratio foams, which expand (shrink) in the transverse direction when stretched (compressed) in the longitudinal direction, have many potential applications in fields such as aerospace and mechanical and biomedical engineering. In this paper, the out-of-plane crushing behaviors of four types of the orthogonal isotropic NPR convex-concave foams (CCF) were extensively studied using an electronic universal testing machine and Instron machine at different strain rates where each test was conducted at a constant compressive velocity under uniaxial compression. Strain rate effect on mechanical properties of these foams is experimentally studied. When the strain rate increases, the compressive force enhancement of the foams is obvious and varies with different specimens. The difference in energy absorption and deformation patterns for these foams between quasi-static and dynamic loading conditions is also analyzed. We find that the deformation patterns for the specimens are not only related to the compressive velocities but also the topologies of the specimens. The research in this paper is expected to be meaningful for the optimization design of the foam structures/materials widely used in the fields of aerospace and mechanical and biomedical engineering.


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