A distributed decision support system for turning and milling operations using the internet

The machine tool industry is highly dependent on the tooling which is needed to machine the components used to make the range of products seen in today's society. The range of tooling available to machinists is prolific and subject to continual growth. Those engineers faced with the task of process planning require advanced systems to support the decisions that need to be made for the production process to operate smoothly. The tooling data made available by these systems is a key factor in defining the efficiency with which the production processes can be carried out. This research examines the technical decision support systems made available to industrialists and highlights the scope to provide tooling engineers with up-to-date tooling performance and use data that can be used both in the planning stages as well as dealing with problems encountered during production. Specifically, this research identifies the role performed by widespread tool trials, associated with new tools or new materials, and goes on to show how the information obtained from tool trials can be collated in a structured manner and used to enhance the provision of data with which to carry out the process planning task. The goal of this research was to develop and implement a framework capable of collecting and disseminating data related to tool trials in a coherent and supportive fashion using distributed methods. This target resulted in the deployment of a system named JadeT, which is capable of receiving and analysing data from tool trials and subsequently enhancing the process planning task by basing cutting parameter selection on a combination of fundamental cutting parameter algorithms in parallel with using the approved data generated from tool trials. The JadeT system was tested via the creation of a database using actual tool trial reports, and the manner in which this data was used to provide cutting parameters was analysed. The JadeT system has been developed, deployed and evaluated. The opportunity to use data contained within tool trial reports to support process planning tasks has been identified and exploited. The testing of JadeT indicates that the system fulfils the initial goals and was able to provide suggestions for further research in this area

The evolutionary emergence of neural organisation in computational models of primitive organisms

Over the decades, the question why did neural organisation emerge in the way that it did? has proved to be massively elusive. Whilst much of the literature paints a picture of common ancestry the idea that a species at the root of the tree of nervous system evolution spawned numerous descendants the actual evolutionary forces responsible for such changes, major transitions or otherwise, have been less clear. The view presented in this thesis is that via interactions with the environment, neural organisation has emerged in concert with the constraints enforced by body plan morphology and a need to process information eciently and robustly. Whilst these factors are two smaller parts of a much greater whole, their impact during the evolutionary process cannot be ignored, for they are fundamentally signicant. Thus computer simulations have been developed to provide insight into how neural organisation of an articial agent should emerge given the constraints of its body morphology, its symmetry, feedback from the environment, and a loss of energy. The first major finding is that much of the computational process of the nervous system can be ooaded to the body morphology, which has a commensurate bearing on neural architecture, neural dynamics and motor symmetry. The second major finding is that sensory feedback strengthens the dynamic coupling between the neural system and the body plan morphology, resulting in minimal neural circuitry yet more ecient agent behaviour. The third major finding is that under the constraint of energy loss, neural circuitry again emerges to be minimalistic. Throughout, an emphasis is placed on the coupling between the nervous system and body plan morphology which are known in the literature to be tightly integrated; accordingly, both are considered on equal footings

An evaluation of the performance of multi-static handheld ground penetrating radar using full wave inversion for landmine detection

This thesis presents an empirical study comparing the ability of multi-static and bi-static, handheld, ground penetrating radar (GPR) systems, using full wave inversion (FWI), to determine the properties of buried anti-personnel (AP) landmines. A major problem associated with humanitarian demining is the occurrence of many false positives during clearance operations. Therefore, a reduction of the false alarm rate (FAR) and/or increasing the probability of detection (POD) is a key research and technical objective. Sensor fusion has emerged as a technique that promises to significantly enhance landmine detection. This study considers a handheld, combined metal detector (MD) and GPR device, and quantifies the advantages of the use of antenna arrays. During demining operations with such systems, possible targets are detected using the MD and further categorised using the GPR, possibly excluding false positives. A system using FWI imaging techniques to estimate the subsurface parameters is considered in this work.A previous study of multi-static GPR FWI used simplistic, 2D far-field propagation models, despite the targets being 3D and within the near field. This novel study uses full 3D electromagnetic (EM) wave simulation of the antenna arrays and propagation through the air and ground. Full EM simulation allows the sensitivity of radio measurements to landmine characteristics to be determined. The number and configuration of antenna elements are very important and must be optimised, contrary to the 2D sensitivity studies in (Watson, Lionheart 2014, Watson 2016) which conclude that the degree (number of elements) of the multi-static system is not critical. A novel sensitivity analysis for tilted handheld GPR antennas is used to demonstrate the positive impact of tilted antenna orientation on detection performance. A time domain GPR and A-scan data, consistent with a commercial handheld system, the MINEHOUND, is used throughout the simulated experiments which are based on synthetic GPR measurements.Finally, this thesis introduces a novel method of optimising the FWI solution through feature extraction or estimation of the internal air void typically present in pressure activated mines, to distinguish mines from non-mine targets and reduce the incidence of false positives

Development of a methanol to hydrocarbons process over zeolite coatings in a microstructured reactor

In this work, the hydrothermal synthesis of ZSM-5 and its coating with controllable crystal size and Si/Al ratio has been performed. The obtained catalysts have been studied in the methanol to hydrocarbon (MTH) reaction. This reaction is the last step in an integrated fuel processor for the conversion of bio resources to liquid fuels. The development of ZSM-5 coatings has been supported by advanced characterization and testing of catalysts for the determination of property/performance relationships. An optimal synthesis time of 72 h was found to provide the highest crystallinity of ZSM-5 coatings. The larger crystal size of ZSM-5 coatings leads to a higher selectivity towards gasoline (C8-11) hydrocarbons. The selectivity towards the gasoline fraction over ZSM-5 coatings with a thickness of 14 μm was similar to that of an industrial ZSM-5 catalyst, however the yield of the undesirable aromatics by-products was reduced by half due to shorter diffusion pathways in thin catalyst layers. In an attempt to improve the yield of the C8-11 hydrocarbons, two post-synthesis modifications have been performed: Ca ion-exchange and desilication by alkaline treatment. The maximum gasoline selectivity over Ca-H-ZSM-5 was observed at a Ca/H ratio of 0.1 while the longest lifetime in the reaction was observed at the ratio of 0.2. Mesoporosity has been introduced into microporous ZSM-5 catalysts. The obtained meso-microporous ZSM-5 coating show 3 times lifetime and 2.7 times selectivity towards C8-11 hydrocarbon fraction than microporous coating in the MTH reaction. Lumped kinetics of MTH reaction over H-ZSM-5 were used to design a microstructured reactor/heat-exchanger (MRHE) with reaction channels coated with the ZSM-5 catalyst. 2D and 3D convection and conduction heat transfer models coupled with the MTH reaction kinetics were employed to investigate temperature distribution in the MRHE. The effect of the dimension of the microreactor/ heat-exchanger and flow condition on the temperature field has been studied. The 2D model under-predicts the magnitude of temperature gradient. The optimised reactor configuration shows a temperature gradient of 21 K in the reaction channels

Characterization of high cycle fatigue and laser-aided machining and polishing of additively manufactured materials

“Additive manufacturing (AM) and laser-aided machining and polishing (LAMP) of materials are emerging manufacturing processes both for research and industrial sectors. The AM process can manufacture near-net-shape parts with complex geometries. Meanwhile, the LAMP process integrated with an AM system offers a high processing rate, minimum heat-affected zone, and easily adjustable process parameters during machining and polishing. In mechanical properties characterization of AM metals and alloys, fatigue is a vitally important test method to understand the behavior of materials in cycling loading and unloading circumstances since most mechanical failures of structures are due to fatigue. To characterize AM metal fatigue behavior, it is also crucial to understand and analyze how the fabrication process parameters, build orientations, and defect formations affect the ability of materials to resist fatigue failure. This research aims to study the needed fundamental knowledge for a high-speed fatigue testing method with miniature specimens and investigate the effect of build process parameters on the high cycle fatigue performance of AM materials. In this study, the implementation of miniature specimens with increased surface area and uniform stress distribution within gauges captures a large population of surface and subsurface defects, reduces the stress gradient effect, maintains symmetric loading, minimizes material and test equipment costs, and decreases sample preparation and test time. The acquired knowledge from this study helps understand the influence of defects on the fatigue behavior of AM materials and determine the high fatigue strength yielding process parameters. Since the fatigue strength of materials can be improved by machining and polishing part surfaces, the objectives of this research also include developing a multilaser LAMP process and investigating the effect of different process parameters on part surface quality improvements. The research results lead to new knowledge that could benefit a wide range of manufacturing industries”--Abstract, page iv

Holographic Sensors for the Detection of Liquid Phase Analytes

The aim of this project is to design, fabricate and study experimentally photonic structures created by holographic lithography for application in sensing. The aim is to modify the photonic structures with analyte sensitive materials and view of their application in environmental and biomedical sensing. Two types of photonic structures were investigated in these studies: modified surface relief holographic gratings and volume holographic gratings

Proceedings of the COST Action TU1403 : Adaptive Facades Network Final Conference

info:eu-repo/semantics/publishedVersio

Development of Optimal Total Hip Joint Replacement

Total hip replacement (THR) is a surgical process in which the hip joint is replaced by a hip prosthesis. It is one of the most popular and cost effective surgery. In particular in 2014, 83,125 primary procedures were recorded. Some of these operations need to be carried out again for different reasons after sometime. These are called revision (replacement of the prosthesis) procedures. Important studies and statistics suggest that the number of THR procedures is projected to increase by almost 175% by 2030. Aseptic loosening appears to be the most significant cause of failure in THR. Aseptic loosening might lead to revision surgery and in turn can be avoided by enhancing the stability and durability of the hip replacement. Primary stability attained after surgery is a determinant issue for the long-term stability of cementless hip arthroplasty. Primary stability is the level of relative micromotion between the femur and the prosthesis induced via the physiological joint forces following the surgery. The hip prosthesis is also exposed to dynamic loadings and activities of daily living, which can induce the stress distribution on the prosthesis of the hip joint model and affect the durability of the implant. The aim of this study is to develop an optimal total hip replacement (THR) implant with new and improved design features to achieve stability and durability. The micromotion between bone and implant interface and the stress distribution on the prosthesis and femur assembly has been reviewed and investigated. The laboratory testing were carried out on the femur including the compression, torsion and Brinell hardness testing. A compression testing using strain gauge technique done on the hip implant. Finite element analysis software used to simulate all compression and torsion testing assuming the same boundary and loading conditions and subsequently the computational results were compared with the earlier experimental data to verify the experiments and models used. 7 The comparative micromotion studies and findings of other researchers were used beside the clinical follow-up reports on success or failure rates of related hip designs, to justify the best solutions for design factors. In this computational approach researchers usually use finite element methodology to calculate micromotion of elements, sometimes known as migration. The elements exceeding the threshold limit would simulate the migration and subsequently eliminated from the assembly. This procedure recurs until reaching the convergence that derives a stable mechanical equilibrium. One of the restrictions of micromotion analysis was the inability to divide the final results into axial and rotational components. Therefore it would have been inappropriate to eventually conclude the best femoral stem, without considering the sustaining torsional loadings. Another limitation was that the micromotion analysis would not reflect the stress distribution on the hip prosthesis and consequently would ignore the potential high stress concentration that is associated with post operative pain as well as low durability and long-term stability. For these reasons stress analysis was carried out under dynamic loadings of nine different activities to examine the von Mises stress, shear stress and principal stress distribution of a cementless hip implant. In each activity realistic boundary and loading conditions of a complete assembly of femur and hip implant were investigated which includes defining of many variables including different geometry, material properties, boundary conditions, forces and moments of varying magnitude and orientation over specific time intervals. The critical points and areas that were developed in the entire 3D model were evaluated and explained. The finite element analysis which verified by experimental testing and hold the clinical relevance were used to decide the best optimal hip stem design amongst different presented design concepts. This was accompanied and improved with further stress analysis of different design factors to get the final optimal model. High offset stem option is a unique feature that helps tightening the abductor and boosts the hip implant stability with the ability to adjust neck and offset. It gives a surgeon more options to fix the most accurate offset and do the operation more effectively. The final optimal design and its advantages were presented in the last chapter