Non-principal surface waves in deformed incompressible materials

The Stroh formalism is applied to the analysis of infinitesimal surface wave propagation in a statically, finitely and homogeneously deformed isotropic half-space. The free surface is assumed to coincide with one of the principal planes of the primary strain, but a propagating surface wave is not restricted to a principal direction. A variant of Taziev’s technique [R.M. Taziev, Dispersion relation for acoustic waves in an anisotropic elastic half-space, Sov. Phys. Acoust. 35 (1989) 535–538] is used to obtain an explicit expression of the secular equation for the surface wave speed, which possesses no restrictions on the form of the strain energy function. Albeit powerful, this method does not produce a unique solution and additional checks are necessary. However, a class of materials is presented for which an exact secular equation for the surface wave speed can be formulated. This class includes the well-known Mooney–Rivlin model. The main results are illustrated with several numerical examples

Application of an experimental design to study AISI 4340 and 300M steels electropolishing in a concentrated perchloric/acetic acid solution

The objective of this study was to assess AISI 4340 and 300 M steels electropolishing performance in aconcentrated perchloric/acetic acid electrolyte. The statistical analysis on a two-level fractional design(FFD)24-1was proposed to define an adequate tool to describe the dissolved thickness and thefinalsurface via arithmetic roughness Ra. A compromise zone was defined for each steel by considering allthe requirements for both responses of each steel: dissolved thickness between 15–17μm andarithmetic roughness criteria less than 0.06μ

Surface stability of nonlinear magnetoelastic solids

The present paper proposes to identify surface stability when a magnetoelastic half-space is subjected to a pure homogeneous pre-deformation and to a magnetic field normal to its (plane) boundary. Clearly, the aim is to find the critical stretch ratio beyond which surface instabilities may develop, or in other words, to establish a bifurcation criterion based on the incremental static solution of the boundary value problem. We want to analyse how the presence of a coupling between magnetism and nonlinear elasticity modify the conditions of stability.This work was supported by grants from the Minist`ere d´el´egu´e`a la recherche (France), the Minist`ere des Affaires´etrang`eres (France), the University of Glasgow (Scotland), the CNRS (France), and the Royal Society (UK). The authors are also verygrateful to G´erard Maugin for valuable suggestions

Guidelines for designing a realistic peripheral venous catheter insertion simulator: A literature review

International audienceA literature review was conducted to develop more realistic medical simulators that better prepare aspiring health professionals to perform a medical procedure in vivo. Thus, this review proposes an approach that might assist researchers design improved medical simulators, particularly new materials that would enhance the sensation of touch for skin substitutes. By targeting the current needs in the field of simulation learning, we concluded that peripheral venous catheter insertion (PVCI) simulators lack realistic haptic feedback. Enhanced PVCI simulators will accelerate the mastery of the medical procedure, thus decreasing the number of failures in patients and costs related to this procedure

Mechanical properties of excised human skin

In this study we have investigated in influence of location, gender and orientation on the deformation characteristics of 55 samples of human excised skin. Uniaxial tensile tests were carried out at a strain rate of 0.012s-1 on excised human skin from the back. The deformation characteristics of skin (Ultimate Tensile Strength (P<0.0001), Failure Strain (P=0.0177), Young s Modulus (P<0.0076), Initial Slope (P=0.0375) and Strain Energy (P=0.0101)) were found to be dependent upon the orientation of specimens with respect to the Langer s Lines. The location of specimens on the back was also found to have a significant effect on the Ultimate Tensile Strength (P =0.0002), the Young s Modulus (P=0.0017) and the Strain Energy (P=0.005).Irish Research Council for Science and Engineering Technology and the Irish Department of Justice Equality and Law Refor

Packaging and Food: A Complex Combination

The advent of packaging materials in the modern food industry has deeply changed the relationship between people and foods. Food packages have progressively been turned into essential element for the sale and the consumption of food products. On these bases, packaged foods can become communicative media of values and information: the user receives and understands these data by means of suitable tools of physical, cultural and personal nature. Functional and communicative requirements of food packaging are continuously evolving: the careful analysis of these factors should be recommended because of their influence on chemistry of foods, food technology, biochemical interactions between different food phases, and chemistry of food packaging. This section is dedicated to the study and the ‘chemical’ interpretation of food packaging requirements