Papers by Keyword: Elastic Behaviour

Abstract: The study of the mechanical behaviour of single-walled carbon nanotube heterojunctions has been carried out, implementing nanoscale continuum approach. A three-dimensional finite element model is used in order to evaluate the elastic behaviour of cone heterojunctions. It is shown that the bending rigidity of heterojunctions is sensitive to bending conditions. The torsional rigidity does not depend on torsion conditions. Both rigidities of the heterojunction are compared with those of the thinner and thicker constituent nanotubes.

Abstract: The elastic response of a metastable β titanium alloy, Ti-25Nb-3Zr-3Mo-2Sn, is characterised. The effects of processing and heat treatment on phase composition and mechanical behaviour are reported. The alloy exhibits pseudoelastic behaviour which is related to the reversible formation of the stress induced α" phase. The solution treated condition displays the greatest pseudoelasticity and the hot rolled condition the least. Tensile deformation reduces the modulus of the alloy. This is due to increases in the relative proportions of the low modulus α" phase.

Abstract: The paper reports about different kind of sutures, their suitability and performance. An ideal suture should possess many characteristics such as - easy to handle, bio-compatibility, minimal tissue reaction, resistance to bacterial growth, adequate tensile strength and elasticity, knot security, strength loss versus healing rate of tissues. Selection of suture is often very complex for satisfying host of physical, mechanical and biological properties, and fulfilling contradictory requirements in varied applications. The paper develops an understanding about the selection of suture depending on the varied requirement. Past research work pertaining to the development of suture as reported in this paper, provides insight about the suitability of different surgical sutures and possible direction of future research.

Abstract: In this work the elastic behaviour of metallic powder compacts is studied. Cylindrical specimens with different levels of density have been submitted to uniaxial compression tests with loading and unloading cycles. The analysis of the elastic loadings shows a non linear elasticity which can be mathematically represented by means of a potential law. Results are explained by assuming that the total elastic strain is the contribution of two terms one deriving from the hertzian deformation of the contacts among particles and another that takes into account the linear elastic deformation of the powder skeleton. A simple model based in a one pore unit cell is presented to support the mathematical model.

Abstract: The purposes of stitching multi-axial warp knitted fabric preform prior to the fabrication of the composite materials by resin-transfer molding technique are to improve the resistance to delamination and to increase the out-of-plane properties of the composite materials for structural integrity. The influence of the through-the-thickness stitching on the elastic properties and behaviors of the multi-axial warp knit fabric composites is studied. An analytical model based on the representative volume is proposed to predict the elastic properties of the stitched multi-axial warp knit fabric composite materials. The fiber volume ratios determined by geometric parameters set by the representative volume and elastic behaviors of the in-situ constituent materials are used for the predictions. The crucial step in the analysis is to correlate the averaged stress states in the constituents by adopting bridging matrix. The predicted results are compared with the experimental results. It is found that the predicted results are in reasonably good agreement with the experimental results.