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A stochastic modelling framework for predicting flexural properties of ultra-thin randomly oriented strands
Get PDFA stochastic modelling framework is developed to predict the flexural properties of high-strength sheet moulding compounds made of randomly oriented ultra-thin carbon fibre-reinforced thermoplastic prepreg tapes. The model enables reliable designs using ultra-thin randomly oriented strands with less testing, leading to potential applications in automotive primary structures. The stochastic model is based on a Monte Carlo simulation. The flexural modulus is predicted using classical laminate theory, while the flexural strength is predicted by following a Weibull distribution. Fibre discontinuities are considered through stress concentrations introduced by tape overlaps. The results are validated against new 3-point bending and previously reported 4-point bending experimental results. A scaling effect on strength and scatter is predicted, and its implications for structural applications are also discussed.The work was supported by the Royal Society [IEC\R3\213017]Advanced Composite Material
Viruses in raw and treated potable waters: prevalence and monitoring methods data
No full textData associated with the above named manuscriptUK Water Industry Researc
Identifying the exaptation potential of supply chain resilience capabilities during COVID-19: insights from Australia
Get PDFWhat happens to newly built resilience capabilities when the pandemic is over? Using the concept of exaptation, we investigate how supply chain organizations have repurposed supply chain resilience capabilities post-pandemic. In particular, we examine the degree of ambidexterity capabilities to identify the exaptation potential from the newly acquired supply chain resilience capabilities during a disruptive event. In this paper, we (1) adopt a framework that depicts four types of different exaptation potential for supply resilience based on the management constructs of exploitation and exploration capabilities and (2) use the results from a related survey among 447 supply chain managers in Australia to subsequently analyse the exaptation potentials post COVID-19. The integration of the exaptation potential into supply chain literature opens a new chapter on how resilience capabilities are utilized, and we found that the majority of supply chains are able to simultaneously pursue and develop exploitative and exploratory capabilities.Supported by the Queensland University of Technology’s (QUT) School of Management
Data - Immobilisation of anaerobic digestate supplied nitrogen into soil microbial biomass is dependent on lability of high organic carbon mat
No full textResearch data for a 150 day incubation study to determine the effects of mixing high organic carbon materials into anaerobic digestate on soil microbial immobilisation of digestate supplied nitrogen and on soil microbial communities. This dateset contains raw data on microbial biomass carbon and nitrogen, soil available nitrogen (ammonium-N and total oxides of nitrate-nitrite), total soil nitrogen, and PLFA biomarkers.FoodBioSystems: biological processes across the Agri-Food system from pre-farm to post-for
Platform health management for aircraft maintenance – a review
Get PDFAircraft health management has been researched at both component and system levels. In instances of certain aircraft faults, like the Boeing 777 fuel icing problem, there is evidence suggesting that a platform approach using an Integrated Vehicle Health Management (IVHM) system could have helped detect faults and their interaction effects earlier, before they became catastrophic. This paper reviews aircraft health management from the aircraft maintenance point of view. It emphasizes the potential of a platform solution to diagnose faults, and their interaction effects, at an early stage. The paper conducts a thorough analysis of existing literature concerning maintenance and its evolution, delves into the application of Artificial Intelligence (AI) techniques in maintenance, explains the rationale behind their employment, and illustrates how AI implementation can enhance fault detection using platform sensor data. Further, it discusses how computational severity and criticality indexes (health indexes) can potentially be complementary to the use of AI for the provision of maintenance information on aircraft components, for assisting operational decisions.Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineerin
Trapping and bypassing of suspended particulate matter, particulate nutrients and faecal indicator organisms in the river-estuary transition zone of a shallow macrotidal estuary
Get PDFHydrodynamic controls of the transport of suspended particulate matter (SPM), particulate nutrients and faecal indicator organisms (FIOs) in the river-estuary transition zone (RETZ) of a shallow macrotidal estuary were studied on tidal and seasonal timescales. The RETZ was found to be a conduit for SPM rather than a zone of particle accumulation during spring tides, with complex size fractionation and biogeochemical exchanges of particulate nutrient/FIO compositions. The downstream RETZ was characterised by flood-dominant currents, but with ebb-dominant turbulence due to the suppression of flood tide turbulence by salinity stratification created by lateral convergence; this produced a net seaward mass transport of SPM. Without lateral convergence in the narrower upstream RETZ, flood-dominant currents and flood-dominant turbulence were experienced. Hence the RETZ exported SPM landwards from its upper end and seawards from its lower end — a process observed throughout the year during spring tides and low-to-mean river flows. During neap tides when SPM concentrations were reduced, the RETZ became a zone of minor particle accumulation as its lower end imported SPM landwards from the estuary and its upper end imported SPM seawards from the river. During a river flood event, net SPM flux was significantly increased and was seawards throughout the RETZ. SPM mass concentration and carbon, nitrogen, phosphorous, and FIO concentrations peaked due to local resuspension and advection of an ephemeral estuarine turbidity maximum (ETM). The ETM formed on the advancing flood tide due to entrainment of material from intertidal flats. Flocculation and settling occurred at high slack water. The ETM was reconstituted by entrainment on the ebb and was composed of larger flocs than on the flood. Particulate nutrients and FIOs were associated with flocs in the 10–200 μm range but not with smaller or larger flocs. SPM concentrations in the resuspension component and ETM exceeded microbial water quality standards, emphasising the need for monitoring practices that consider tidal dynamics. The results from this study showing periodic SPM export from, rather than prolonged accumulation in, the RETZ and the influence of particle size fractionation on biogeochemical fluxes in the RETZ, are likely to be transferable to many other embayment-type estuaries on macrotidal coasts.Science of The Total Environmen
Rotary mount design for a chromatic confocal sensor, involving additive manufacturing and an opened air bearing
Get PDFShore, Paul - Associate SupervisorIn the field of high energy physics, the characterisation and positioning in space
of a wire with a diameter of 0.1 mm is one of the steps to increase the precision
of future accelerators’ pre-alignment. This reference wire is measured within a
high accuracy Coordinate Measuring Machine (CMM) to reduce its positioning
uncertainty. No sensor could measure the wire position within the targeted
uncertainty. This thesis addresses this issue by proposing a design for the Shape
Evaluating Sensor: High Accuracy & Touchless (SESHAT).
The SESHAT operates a chromatic confocal sensor. The sensor is fixed to a rotor
with a radial opening to allow the stretched wire to traverse it. This rotor is guided
by a high precision air bearing controlled by a piezoelectric actuator. The mass
limit for the stylus system of the CMM entailed the additive manufacturing of a
hollow rotor. The high likelihood of particles on the wire surface involved a form
deviation capability for the SESHAT, to reduce position measurement
uncertainty.
The aim of the research was to design a sensor enabling the Leitz Infinity CMM
to perform non-contact form measurement on the PACMAN reference wire to
permit its axis positioning with an uncertainty such that 3σ < 0.5 µm. The novelty
emphasised in this thesis is focused on three main contributions. The form
measurement uncertainty reduction obtained by using a chromatic confocal
sensor for non-contact measurement on a wire surface is the first contribution. A
mathematical model describing the behaviour of air pads over a through hole in
the bearing surface composes the second contribution to knowledge. The
demonstrated ability to obtain a micrometric form deviation on a rotary symmetric
complex shape generated by additive manufacturing of titanium is the third
contributionPhD in Manufacturin
Research progress on bio-inspired flapping-wing rotor micro aerial vehicle development
Get PDFFlapping-wing rotor (FWR) is an innovative bio-inspired micro aerial vehicle capable of vertical take-off and landing. This unique design combines active flapping motion and passive wing rotation around a vertical central shaft to enhance aerodynamic performance. The research on FWR, though relatively new, has contributed to 6% of core journal publications in the micro aerial vehicle field over the past two decades. This paper presents the first comprehensive review of FWR, analysing the current state of the art, key advances, challenges, and future research directions. The review highlights FWR’s distinctive kinematics and aerodynamic superiority compared to traditional flapping wings, fixed wings, and rotary wings, discussing recent breakthroughs in efficient, passive wing pitching and asymmetric stroke amplitude for lift enhancement. Recent experiments and remote-controlled take-off and hovering tests of single and dual-motor FWR models have showcased their effectiveness. The review compares FWR flight performance with well-developed insect-like flapping-wing micro aerial vehicles as the technology readiness level progresses from laboratory to outdoor flight testing, advancing from the initial flight of a 2.6 g prototype to the current free flight of a 60-gram model. The review also presents ongoing research in bionic flexible wing structures, flight stability and control, and transitioning between hovering and cruise flight modes for an FWR, setting the stage for potential applications.Journal of Bionic Engineerin
The role of social capital in project managers’ responses to complexities
Get PDFSocial capital has been demonstrated to be an important commodity for managers in project-based operations. This paper examines the role of social capital in the work of 36 managers from three engineering firms, using qualitative case data. We ask the research question ‘How is Social Capital used by Project Managers in responding to complexities?’ We derive an improved understanding of how social capital is used in responding to their context. To do this, we draw on two established bodies of work. First, we use the lived experience of the complexity faced by the managers to describe the context. Secondly, we use social capital theory to examine what elements of social capital are employed in response. The interchange between these is initially framed with ‘contextual complexities’ as stimulus and the 'social capital employed’ as response. Our findings show the temporal dynamics of complexity, whereby responses are not isolated but dependent upon both recent experience and expectations of future events. We also show the importance of social relationships in developing valuable recursive patterns of interaction in the project context.EURAM 2024: Fostering Innovation to Address Grand Challenge
Efficient and near-optimal global path planning for AGVs: a DNN-based double closed-loop approach with guarantee mechanism
Get PDFIn this article, a novel global path planning approach with rapid convergence properties for autonomous ground vehicles (AGVs) named neural sampling rapidly exploring random tree (NS-RRT*) is proposed. This approach has a three-layer structure to obtain a feasible and near-optimal path. The first layer is the data collection stage. Utilizing the target area adaptive rapidly exploring random tree (TAA-RRT*) algorithm to establish a collection of paths considering the initial noise disturbance. To enhance network generalization, an optimal path backward generation (OPBG) strategy is introduced to augment the dataset size. In the second layer, the deep neural network (DNN) is trained to learn the relationships between the states and the sampling strategies. In the third layer, the trained model is used to guide RRT* sampling, and an efficient guarantee mechanism is also designed to ensure the feasibility of the planning task. The proposed algorithm can assist the RRT* algorithm in efficiently obtaining optimal or near-optimal strategies, significantly enhancing search efficiency. Numerical results and experiments are executed to demonstrate the feasibility and efficiency of the proposed method.IEEE Transactions on Industrial Electronic