Showing papers on "Auxetics published in 2002"

Auxetic polypropylene fibres:Part 1 - Manufacture and characterisation

Abstract: The term 'auxetic' is applied to materials that possess a negative Poisson's ratio ν. The use of auxetic polymers has been limited because of problems with deploying them in their fabricated forms, i.e. as 10 mm diameter cylinders. This paper reports the successful development of a processing route to produce a more useful and usable form of auxetic polymeric material, namely fibres. A conventional polymer processing technique (melt spinning) is the basis of this technique, with novel modifications. Video extensometry was used to measure the Poisson's ratio and a value of ν = -0.60±0.05 was obtained.

Simultaneous optimization of the electromagnetic and mechanical properties of honeycomb materials

Abstract: In this work a combined analysis of the out-of-plane mechanical and dielectric properties of auxetic re-entrant honeycombs is performed. Experimental and numerical simulations are carried out to evaluate the correlation between the anisotropicity of the transverse mechanical properties (shear and compressive modulus) and the permittivity tensor of general and auxetic (Negative Poisson's ratio) honeycombs. Different numerical and experimental techniques have been applied to obtain the mechanical and dielectric properties of genral and auxetic honeycombs versus the core material and unit cell geometry parameters. The results are evaluated to assess the feasibility of this kind of cellular solid for electromagnetic screen applications with high structural integrity performance.