다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

비만아 부모의 돌봄 경험: q 방법론

Materials and structures with negative Poisson's ratio exhibit a counter-intuitive behaviour. Under uniaxial compression (tension), these materials and structures contract (expand) transversely. The materials and structures that possess this feature are also termed as 'auxetics'. Many desirable properties resulting from this uncommon behaviour are reported. These superior properties offer auxetics broad potential applications in the fields of smart filters, sensors, medical devices and protective equipment. However, there are still challenging problems which impede a wider application of auxetic materials. This review paper mainly focuses on the relationships among structures, materials, properties and applications of auxetic metamaterials and structures. The previous works of auxetics are extensively reviewed, including different auxetic cellular models, naturally observed auxetic behaviour, different desirable properties of auxetics, and potential applications. In particular, metallic auxetic materials and a methodology for generating 3D metallic auxetic materials are reviewed in details. Although most of the literature mentions that auxetic materials possess superior properties, very few types of auxetic materials have been fabricated and implemented for practical applications. Here, the challenges and future work on the topic of auxetics are also presented to inspire prospective research work. This review article covers the most recent progress of auxetic metamaterials and auxetic structures. More importantly, several drawbacks of auxetics are also presented to caution researchers in the future study.

Auxetic metamaterials and structures: a review

Mechanical design and multifunctional applications of chiral mechanical metamaterials: A review

The work describes the mechanical performance of a metal rubber particles (MRP) damper design based on an auxetic (negative Poisson’s ratio) cellular configuration. The auxetic damper configuration is constituted by an anti-tetrachiral honeycomb, where the cylinders are filled with the MRP material. The MRP samples have been subjected to quasi-static loading to measure the stiffness and loss factor from the static hysteresis curve. A parametric experimental analysis has been carried out to investigate the effect of relative density and filling percentage on the static performance of the MRP, and to identify design guidelines for best use of MRP devices. An experimental assessment of the integrated auxetic-MRP damper concept has been provided through static and dynamic force response techniques. (Some figures may appear in colour only in the online journal)

https://iopscience.iop.org/article/10.1088/0964-1726/22/8/084012/pdf

A nonlinear auxetic structural vibration damper with metal rubber particles

Dynamic modeling and vibration characteristics analysis of the aero-engine dual-rotor system with Fan blade out

The work describes the manufacturing and testing of metal rubber (MR) samples produced from nickel-based superalloys, and subjected to compression loading in quasi-static regime, three batches of MRs with different relative densities have been fabricated, and their mechanical properties (tangent modulus, loss factor and Poisson's ratio) have been investigated at different maximum strains, and under cyclic loading. The experiments show the significant effect of the MRs' relative density over the global mechanical compression properties, with the tangent modulus increasing and the loss factor from the hysteretic cycles decreasing in samples with higher density. At low strain level, metal rubber appears to behave like a zero Poisson's ratio material. The results show the effectiveness in controlling the mechanical properties of nickel-based metal rubber by careful adjusting of the relative density during manufacturing.

Yanhong Ma

Papers

A nonlinear auxetic structural vibration damper with metal rubber particles

Dynamic modeling and vibration characteristics analysis of the aero-engine dual-rotor system with Fan blade out

Compression mechanics of nickel-based superalloy metal rubber

The mechanics of shape memory alloy metal rubber

Dynamic mechanical behavior of nickel-based superalloy metal rubber