We extend the Rayleigh method for the calculation of the effective conductivity to three-phase composite materials. The materials under study consist of two types of circular cylinders in a periodic arrangement embedded in a matrix. Highly accurate values for lattice sums were obtained using algorithms which have been recently developed. A series of explicit formulations, which are used to faci...

Synopsis A theoretical study of viscoelastic properties of composites is presented with the aim of identifying structures which give rise to a combination of high stiffness and high loss tangent. Laminates with Voigt and Reuss structure, as well as composite materials attaining the Hashin-Shtrikman bounds on stiffness were evaluated via the correspondence principle. Similarly, viscoelastic prop...

One region of the electromagnetic spectrum that is relatively unexploited for materials characterization is the millimeter wave band frequencies roughly between 40 and 300 GHz . Millimeter wave techniques involve free-space noncontacting measurements which have a length scale that makes them ideal for characterizing bulk properties of multicomponent composites where the scale of homogeneity is ...

The subject of the study was the clinical analysis of six different sealing materials over a 12-months period. It was necessary to prove the clinical success of sealing with flowable composite with the use of adhesive system and preventing effect of sealants on caries developement. Our study included children aged from 6 to 15, and we sealed 326 teeth with materials from the group of flowable c...

Alternative research techniques are essential in order to prove the efficacy of graphene dental materials and their viability, especially if we associate them with other materials studied so far. It is important to determine the effects of these techniques because they can demonstrate the viability and credibility of the research on its properties. The purpose of this study was to measure and a...

Composites with the gradient of Young's modulus constitute a new group of biomimetic materials which affect the proper distribution of stresses between the implant and the bone. The aim of this article was to examine the mechanical properties of gradient materials based on carbon fibre-polysulfone composite, and to compare them to the properties of a natural intervertebral disc. Gradient proper...

Light is a readily available and sustainable energy source. Transduction of light into mechanical work or electricity in functional materials, composites, or systems has other potential advantages derived from the ability to remotely, spatially, and temporally control triggering by light. Toward this end, this work examines photoinduced piezoelectric (photopiezoelectric) effects in laminate com...

1. Abstract Natural fibers are being increasingly used to substitute artificial glass and carbon fibers in polymer composites. It is important to know how the mechanical properties of these natural fiber composites compare with those of the traditional glass and carbon fiber composites. Glass and carbon fiber composites are currently being used in many applications that may not require such hig...

Discontinuous fibre composites represent a class of materials that are strong, lightweight and have remarkable fracture toughness. These advantages partially explain the abundance and variety of discontinuous fibre composites that have evolved in the natural world. Many natural structures out-perform the conventional synthetic counterparts due, in part, to the more elaborate reinforcement archi...