AC
Authored
14 records found
Approximating piecewise nonlinearities in dynamic systems with sigmoid functions
Advantages and limitations
In the industry field, the increasingly stringent requirements of lightweight structures are exposing the ultimately nonlinear nature of mechanical systems. This is extremely true for systems with moving parts and loose fixtures which show piecewise stiffness behaviours. Neverthe
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Shipboard DC systems, a Critical Overview
Challenges in Primary Distribution, Power Electronics-based Protection, and Power Scalability
This article gives an overview of challenges in primary distribution, protections, and power scalability for shipboard dc systems. Given that dc technology is in development, several aspects of shipboard systems have not yet been sufficiently devised to ensure the protection and
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Rigid body dynamic response of a floating offshore wind turbine to waves
Identification of the instantaneous centre of rotation through analytical and numerical analyses
Floating Offshore Wind Turbines (FOWT) can harness the abundant offshore wind resource at reduced installation requirements. However, a further decrease in the development risks through higher confidence in the design and analysis methods is needed. The dynamic behaviour of FOWT
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Computationally aware estimation of ultimate strength reduction of stiffened panels caused by welding residual stress
From finite element to data-driven methods
Ultimate limit state (ULS) assessment examines the maximum load-carrying capacity of structures considering inelastic buckling failure. Contrary to the traditional allowable stress principle which is mainly based on experiences, the ULS assessment focuses on explicitly evaluating
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The development of novel energy technologies to meet net zero carbon emission is essential in the provision of solutions to realize an increasing worldwide demand for renewable energy. Floating Offshore Wind Turbine (FOWT) is one of the emerging technologies to exploit the vast w
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Monitoring and evaluating the biofouling state and its effects on the vessel's hull and propeller performance is a crucial problem that attracts the attention of both academy and industry. Effective and reliable tools to address this would allow a timely cleaning procedure able t
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Opportunistic maintenance for offshore wind
A review and proposal of future framework
As new offshore wind development sites move further from shore and existing sites enter their post-subsidy operating period, it is expected that operational expenditure (OpEx) will increase. In order to overcome these challenges, a more flexible and cost-effective maintenance sol
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Computational prediction of underwater radiated noise of cavitating marine propellers
On the accuracy of semi-empirical models
The potential impact of underwater radiated noise from maritime operations on marine fauna has become an important issue. The most dominant noise source on a propeller-driven vessel is propeller cavitation, producing both structure-borne and radiated noise, with a broad spectrum
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Machine learning-based identification of vulnerability factors for masonry buildings in aggregate
The historicalcentre of casentino hit by the 2009 l'aquila earthquake
Seismic events in Italy and worldwide have highlighted the high vulnerability of unreinforced masonry (URM) structures in small historical centres. A key feature of these settlements is to be mostly composed of buildings in aggregate, i.e., interconnected by a more or less struct
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Optimizing Energy Management for Full-Electric Vessels
A Health-Aware Approach with Hydrogen and Diesel Employing Equivalent Consumption Minimization Strategy
The path to zero-emission shipping is deeply connected to full-electric vessels. One major challenge to enable this technology for broader application is the design of optimal energy management (EM). The flexibility of operating load sharing in hybrid energy systems could lead to
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Optimizing Energy Management for Full-Electric Vessels
A Health-Aware Approach with Hydrogen and Diesel Employing Equivalent Consumption Minimization Strategy
The path to zero-emission shipping is deeply connected to full-electric vessels. One major challenge to enable this technology for broader application is the design of optimal energy management (EM). The flexibility of operating load sharing in hybrid energy systems could lead to
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Floating Spar-Type Offshore Wind Turbine Hydrodynamic Response Characterisation
A Computational Cost Aware Approach
The hydromechanics analysis of floating offshore wind turbines is a fundamental and time consuming part of the design process, traditionally analysed with methods of computational fluid dynamics. In this work, an alternative computational framework is suggested, able to significa
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Floating Spar-Type Offshore Wind Turbine Hydrodynamic Response Characterisation
A Computational Cost Aware Approach
The hydromechanics analysis of floating offshore wind turbines is a fundamental and time consuming part of the design process, traditionally analysed with methods of computational fluid dynamics. In this work, an alternative computational framework is suggested, able to significa
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Ship efficiency forecast based on sensors data collection
Improving numerical models through data analytics
In this paper authors investigate the problem of predicting the fuel consumption of a vessel in real scenario based on data measured by the onboard automation systems. The goal is achieved by exploiting three different approaches: White, Black and Gray Box Models. White Box Model
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Contributed
6 records found
Early Stage Fouling Effects Prediction for Yacht Design
A grey-box model approach using operational voyage data
In this thesis a grey-box model is developed to predict the power increase over time due to marine biofouling. Biofouling is known as the undesired adverse effect of living organisms growing on submerged surfaces. Fouling creates roughness on the hull and propeller and thus addit
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Analysing the cost-effectiveness of predictive maintenance programs using a simulation cost model
A case study for the vacuum compressor pumps at Duyvis
In this thesis, a simulation cost model is presented that can be used to assess the cost-effectiveness of a selection of PdM programs. The proposed model combines a discrete event simulation (DES) model with a cost model. It is specifically designed to analyse the PdM programs fo
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On the effect of the heave motion on the run-up flow
The case study of a 2-D rectangular structure
Wave run-up is the vertical water uprush that occurs when an incident wave impacts on a surface-piercing body. This phenomenon is particularly relevant when waves of high steepness interact with large structures as a result of significant nonlinear interactions between incident a
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A Health-Aware Control Strategy for Enhanced Performance and Extended Hybrid Powertrain Lifecycle
A benchmark of different cost functions
The urgent need for marine transportation to reduce CO2 emissions has led to considering alternative energy and storage sources. The resulting increase in the complexity of powerplant architectures led to the development of advanced control strategies to achieve energy savings. A
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Transshipment for the 21st Century
A Novel Approach to Deep Sea-Hinterland Transportation
Transshipment is a key component of modern-day shipping logistics. Container supply chains rely on transhipment hubs to access remote locations. With globalisation driving growth in container trade, maritime congestion is rising at container terminals in ports worldwide. This is
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Design and Operation Optimization of Hybrid Energy Systems for a General Cargo Vessel
Well-to-Wake Emission Analysis and Plant Lifetime Estimation
The Global Shipping industry is responsible for transporting 90% of global commerce and is responsible for 3% of global greenhouse gas (GHG) emissions. Addressing this, the International Maritime Organization (IMO) aims to reduce GHG emissions from international shipping by 40% b
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