Damping constitutes a major source of uncertainty in dynamic analysis and an open issue to experimental and analytical research. After a thorough review of the current views and approaches existing in literature on damping and its appropriate modelling, this paper focuses on the implications of the available modelling options on analysis. As result of a series of considerations, a damping modelling solution for nonlinear dynamic analyses of cantilever RC walls is suggested within the frame of Direct Displacement-Based Design, supported by comparative analyses on wall structures.
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This paper describes the results of a second year Expo project team of Fontys Engineering, department Mechanical Engineering. During this research the design of a configurable damped spring design has been investigated. A calculation tool has been defined and validated using a Nylon 3D printed spring prototype. Also a theoretical design of a stainless steel spring has been made including stress calculations. Finally characterization tests on damping properties have been performed.
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Greenhouses are in need of new monitoring tools, as they size grow bigger and bigger but still using old labour intensive methods ways of caring for the crop. HiPerGreen is set out to create a new tool, which can drive onto the pre-existing heating pipes to provide a birds eye perspective for image analysis purposes. However, clear images are necessary for consistent usable data. This presentation resumes the steps taken during the reporting: the optimisation of a rail based system towards clear images. This is done through analysis of resulting images, understanding vibrations and oscillations, and finally presents results based on prototyping. Moreover, a re-design of the electronics and hardware was also introduce to facilitate prototyping. The results are promising, laying within the requirements.
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In the high-tech mechatronics world, aluminum and steel are well known materials, while carbon fiber is often neglected. In the RAAK project 'Composites in Mechatronics', the use of carbon fiber composites in mechatronics is investigated.
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Validation of a new method for ultrasonic structural health monitoring using advanced signal analysis. This paper presents the results of research on a new method for the monitoring of structural health using ultrasound. Conventional ultrasonic methods use the damping of the first arrival of the echo to determine imperfections, whereas this method uses the total complex echo, which has been subjected to multiple scattering and deflections within the tested material. It is experimentally demonstrated that the method works for health monitoring of a composite flat plate. A reference signal of an undamaged plate was recorded, which was correlated with recorded control signals of a damaged and a doubly damaged plate. To quantify this correlation the parameter fidelity was used. As the control signals are correlated with the reference signal the correlation is supposed to decrease as the plate is damaged and decrease further as the plate is doubly damaged.
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Dynamic stall phenomena carry the risk of negative damping and instability in wind turbine blades. It is crucial to model these phenomena accurately to reduce inaccuracies in predicting design driving (fatigue and extreme) loads. Some of the inaccuracies in current dynamic stall models may be due to the fact that they are not properly designed for high angles of attack and that they do not specifically describe vortex shedding behaviour. The Snel second-order dynamic stall model attempts to explicitly model unsteady vortex shedding. This model could therefore be a valuable addition to a turbine design software such as Bladed. In this paper the model has been validated with oscillating aerofoil experiments, and improvements have been proposed for reducing inaccuracies. The proposed changes led to an overall reduction in error between the model and experimental data. Furthermore the vibration frequency prediction improved significantly. The improved model has been implemented in Bladed and tested against small-scale turbine experiments at parked conditions. At high angles of attack the model looks promising for reducing mismatches between predicted and measured (fatigue and extreme) loading, leading to possible lower safety factors for design and more cost-efficient designs for future wind turbines.
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Dynamic stall phenomena bring risk for negative damping and instability in wind turbine blades. It is crucial to model these phenomena accurately to reduce inaccuracies in predicting design driving (fatigue) loads. Inaccuracies in currentdynamic stall models may be due to the facts that they are not properly designed for high angles of attack, and that they do not 10 specifically describe vortex shedding behaviour. The Snel second order dynamic stall model attempts to explicitly model unsteady vortex shedding. This model could therefore be a valuable addition to DNV GL’s turbine design software Bladed. In this thesis the model has been validated with oscillating airfoil experiments and improvements have been proposed for reducing inaccuracies. The proposed changes led to an overall reduction in error between the model and experimental data. Furthermore the vibration frequency prediction improved significantly. The improved model has been implemented in Bladed and tested 15 against small scale turbine experiments at parked conditions. At high angles of attack the model looks promising for reducing mismatches between predicated and measured (fatigue) loading. Leading to possible lower safety factors for design and more cost efficient designs for future wind turbines.
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Engineering students have to learn to create robust solutions in professional contexts where new technologies emerge constantly and sometimes disrupt entire industries. The question rises if universities design curricula that enable engineering students to acquire these cognitive skills. The Cynefin Framework (Kurtz & Snowden, 2003; Snowden & Boone, 2007) can be used to typify four complexity contexts a system or organisation can be found in: chaos, complex, complicated and obvious.The Cynefin framework made it possible to create the research question for a case-study: To what extend does the Business Engineering curriculum enable bachelors to find business solutions in the complexity contexts of the Cynefin framework? The results show that 80% of the methods are suitable for complicated contexts and no distinction is made between contexts. This means students are taught to approach most contexts in the same way and are not made aware of differences between the contexts. Making sense of the methods in the curriculum with the Cynefin framework was insightful and suggestions for improvement and further research could be substantiated
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In recent years, a step change has been seen in the rate of adoption of Industry 4.0 technologies by manufacturers and industrial organizations alike. This article discusses the current state of the art in the adoption of Industry 4.0 technologies within the construction industry. Increasing complexity in onsite construction projects coupled with the need for higher productivity is leading to increased interest in the potential use of Industry 4.0 technologies. This article discusses the relevance of the following key Industry 4.0 technologies to construction: data analytics and artificial intelligence, robotics and automation, building information management, sensors and wearables, digital twin, and industrial connectivity. Industrial connectivity is a key aspect as it ensures that all Industry 4.0 technologies are interconnected allowing the full benefits to be realized. This article also presents a research agenda for the adoption of Industry 4.0 technologies within the construction sector, a three-phase use of intelligent assets from the point of manufacture up to after build, and a four-staged R&D process for the implementation of smart wearables in a digital enhanced construction site.
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