4,246 research outputs found
Design of an integrated shallow water wave experiment
The experimental design and instrumentation for an integrated shallow-water surface gravity wave experiment is discussed. The experiment required the measurement of the water surface elevation, meteorological parameters, and directional spectra at a number of locations on a shallow lake. In addition, to acquire data under a wide range of conditions, an experimental period of three years was required. A system of telephone and radio modem links were installed to enable real-time monitoring of instrument performance at eight separate measurement locations on the lake. This system also enabled logging sessions to be optimized to ensure the maximum possible data return from this extended experimentIEEE Oceanic Engineering Societ
Modelling mechanical percolation in graphene-reinforced elastomer nanocomposites
Graphene is considered an ideal filler for the production of multifunctional
nanocomposites; as a result, considerable efforts have been focused on the
evaluation and modeling of its reinforcement characteristics. In this work, we
modelled successfully the mechanical percolation phenomenon, observed on a
thermoplastic elastomer (TPE) reinforced by graphene nanoplatelets (GNPs), by
designing a new set of equations for filler contents below and above the
percolation threshold volume fraction (Vp). The proposed micromechanical model
is based on a combination of the well-established shear-lag theory and the
rule-of-mixtures and was introduced to analyse the different stages and
mechanisms of mechanical reinforcement. It was found that when the GNPs content
is below Vp, reinforcement originates from the inherent ability of individual
GNPs flakes to transfer stress efficiently. Furthermore, at higher filler
contents and above Vp, the nanocomposite materials displayed accelerated
stiffening due to the reduction of the distance between adjacent flakes. The
model derived herein, was consistent with the experimental data and the reasons
why the superlative properties of graphene cannot be fully utilized in this
type of composites, were discussed in depth.Comment: 29 pages, 12 figure
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