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Full-Text Articles in Mechanical Engineering
Considerations For The Design Optimization Of Floating Offshore Wind Turbine Blades, Evan M. Gaertner
Considerations For The Design Optimization Of Floating Offshore Wind Turbine Blades, Evan M. Gaertner
Doctoral Dissertations
Floating offshore wind turbines are an immature technology with relatively high costs and risk associated with deployment. Of the few floating wind turbine prototypes and demonstration projects deployed in real metocean conditions, all have used standard turbines design for onshore or offshore fixed bottom conditions. This neglects the unique unsteady aerodynamics brought on by floating support structure motion. While the floating platform has been designed and optimized for a given rotor, the global system is suboptimal due to the rotor operating in conditions outside of which it was design for. If the potential offered by floating wind turbines is to …
Time-Dependent Reliability Methodologies With Saddlepoint Approximation, Zhangli Hu
Time-Dependent Reliability Methodologies With Saddlepoint Approximation, Zhangli Hu
Doctoral Dissertations
"Engineers always encounter time-dependent uncertainties that ubiquitously exist, such as the random deterioration of material properties and time-variant loads. Therefore the reliability of engineering systems becomes time-dependent. It is crucial to predict the time-dependent reliability in the design stage, given possible catastrophic consequences of a failure. Although extensive research has been conducted on reliability analysis, estimating the reliability accurately and efficiently is still challenging. The objective of this work is to develop accurate and efficient reliability methodologies for engineering design. The basic idea is the integration of traditional reliability methods with saddlepoint approximation (SPA), which can accurately approximate the tail …
Probabilistic Engineering Analysis And Design Under Time-Dependent Uncertainty, Zhen Hu
Probabilistic Engineering Analysis And Design Under Time-Dependent Uncertainty, Zhen Hu
Doctoral Dissertations
"Time-dependent uncertainties, such as time-variant stochastic loadings and random deterioration of material properties, are inherent in engineering applications. Not considering these uncertainties in the design process may result in catastrophic failures after the designed products are put into operation. Although significant progress has been made in probabilistic engineering design, quantifying and mitigating the effects of time-dependent uncertainty is still challenging. This dissertation aims to help build high reliability into products under time-dependent uncertainty by addressing two research issues. The first one is to efficiently and accurately predict the time-dependent reliability while the second one is to effectively design the time-dependent …