85 research outputs found
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Industry 1.61803: the transition to an industry with reduced material demand fit for a low carbon future
Arising from a discussion meeting in September 2016, this editorial introduces a special issue on the transition to a future industrial system with greatly reduced demand for material production and attempts to synthesize the main findings. The motivation for such a transition is to reduce industrial greenhouse gas emissions, but unlike previous industrial transformations, there are no major stakeholders who will pursue the change for their own immediate benefit. The special issue, therefore, explores the means by which such a transition could be brought about. The editorial presents an overview of the opportunities identified in the papers of the volume, presents examples of actions that can be taken today to begin the process of change and concludes with an agenda for research that might support a rapid acceleration in the rate of change.The work of J.M.A. and A.C.S. on this paper was funded by EPSRC grant reference EP/N02351X/1 and that of A.C.H.S. by EPSRC grant reference EP/K039326/1
Energy Consumption Characterization and Reduction Strategies for Milling Machine Tool Use
Since machine tools are used extensively throughout their functional life and consequently consuming valuable natural resources and emitting harmful pollutants during this time, this study reviews strategies for characterizing and reducing the energy consumption of milling machine tools during their use. The power demanded by a micromachining center while cutting low carbon steel under varied material removal rates was measured to model the specific energy of the machine tool. Thereafter the power demanded was studied for cutting aluminum and polycarbonate work pieces for the purpose of comparing the difference in cutting power demand relative to that of steel
Potential range of impact of an ecological trap network: the case of timber stacks and the Rosalia longicorn
Although the negative impact of timber stacks on populations of saproxylic beetles is a well-known phenomenon, there is
relatively little data concerning the scale of this impact and its spatial aspect. Beech timber stored in the vicinity of the forest
can act as an ecological trap for the Rosalia longicorn (Rosalia alpina), so in this study we have attempted to determine the
spatial range of the impact of a network of timber stacks. Timber stacks in the species’ range in the study area were listed
and monitored during the adult emergence period in 2014–2016. Based on published data relating to the species’ dispersal
capabilities, buffers of four radii (500, 1000, 1600, 3000 m) were delineated around the stacks and the calculated ranges of
potential impact. The results show that the percentage of currently known localities of the Rosalia longicorn impacted by
stacks varies from 19.7 to 81.6%, depending on the assumed impact radius. The percentage of forest influenced by timber
stacks was 77% for the largest-radius buffer. The overall impact of the ecological trap network is accelerated by fragmentation
of the impact-free area. It was also found that forests situated close to the timber stacks where the Rosalia longicorn was
recorded were older and more homogeneous in age and species composition than those around stacks where the species was
absent. Such results suggest that timber stacks act as an ecological trap in the source area of the local population
Railway-induced ground vibrations – a review of vehicle effects
This paper is a review of the effect of vehicle characteristics on ground- and track borne-vibrations from railways. It combines traditional theory with modern thinking and uses a range of numerical analysis and experimental results to provide a broad analysis of the subject area. First, the effect of different train types on vibration propagation is investigated. Then, despite not being the focus of this work, numerical approaches to vibration propagation modelling within the track and soil are briefly touched upon. Next an in-depth discussion is presented related to the evolution of numerical models, with analysis of the suitability of various modelling approaches for analysing vehicle effects. The differences between quasi-static and dynamic characteristics are also discussed with insights into defects such as wheel/rail irregularities. Additionally, as an appendix, a modest database of train types are presented along with detailed information related to their physical attributes. It is hoped that this information may provide assistance to future researchers attempting to simulate railway vehicle vibrations. It is concluded that train type and the contact conditions at the wheel/rail interface can be influential in the generation of vibration. Therefore, where possible, when using numerical approach, the vehicle should be modelled in detail. Additionally, it was found that there are a wide variety of modelling approaches capable of simulating train types effects. If non-linear behaviour needs to be included in the model, then time domain simulations are preferable, however if the system can be assumed linear then frequency domain simulations are suitable due to their reduced computational demand
A Review on the Mechanical Modeling of Composite Manufacturing Processes
© 2016, The Author(s). The increased usage of fiber reinforced polymer composites in load bearing applications requires a detailed understanding of the process induced residual stresses and their effect on the shape distortions. This is utmost necessary in order to have more reliable composite manufacturing since the residual stresses alter the internal stress level of the composite part during the service life and the residual shape distortions may lead to not meeting the desired geometrical tolerances. The occurrence of residual stresses during the manufacturing process inherently contains diverse interactions between the involved physical phenomena mainly related to material flow, heat transfer and polymerization or crystallization. Development of numerical process models is required for virtual design and optimization of the composite manufacturing process which avoids the expensive trial-and-error based approaches. The process models as well as applications focusing on the prediction of residual stresses and shape distortions taking place in composite manufacturing are discussed in this study. The applications on both thermoset and thermoplastic based composites are reviewed in detail
From Architectured Materials to Large-Scale Additive Manufacturing
The classical material-by-design approach has been extensively perfected by materials scientists, while engineers have been optimising structures geometrically for centuries. The purpose of architectured materials is to build bridges across themicroscale ofmaterials and themacroscale of engineering structures, to put some geometry in the microstructure. This is a paradigm shift. Materials cannot be considered monolithic anymore. Any set of materials functions, even antagonistic ones, can be envisaged in the future. In this paper, we intend to demonstrate the pertinence of computation for developing architectured materials, and the not-so-incidental outcome which led us to developing large-scale additive manufacturing for architectural applications
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