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Full-Text Articles in Engineering
Reliability Analysis For Systems With Outsourced Components, Zhengwei Hu
Reliability Analysis For Systems With Outsourced Components, Zhengwei Hu
Doctoral Dissertations
"The current business model for many industrial firms is to function as system integrators, depending on numerous outsourced components from outside component suppliers. This practice has resulted in tremendous cost savings; it makes system reliability analysis, however, more challenging due to the limited component information available to system designers. The component information is often proprietary to component suppliers. Motivated by the need of system reliability prediction with outsourced components, this work aims to explore feasible ways to accurately predict the system reliability during the system design stage. Four methods are proposed. The first method reconstructs component reliability functions using limited …
Theoretical Modeling, Experimental Observation, And Reliability Analysis Of Flow-Induced Oscillations In Offshore Wind Turbine Blades, Pariya Pourazarm
Theoretical Modeling, Experimental Observation, And Reliability Analysis Of Flow-Induced Oscillations In Offshore Wind Turbine Blades, Pariya Pourazarm
Doctoral Dissertations
Offshore wind energy has been growing rapidly due to its capacity for utilizing much larger turbines and thus higher power generation compared to onshore. With the increasing size of offshore wind turbine rotors, the design criteria used for the blades may also evolve. Increased flexibility in blades causes them to be more susceptible to experiencing flow-induced instability. One of the destructive aero-elastic instabilities that can occur in flexible structures subjected to aerodynamic loading is coupled-mode flutter. Coupled-mode flutter instability has not been a design driver in the current wind turbine blades, however, considering the industry tendency in utilizing longer and …
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 …
Robust Multichannel Functional-Data-Analysis Methods For Data Recovery In Complex Systems, Jian Sun
Robust Multichannel Functional-Data-Analysis Methods For Data Recovery In Complex Systems, Jian Sun
Doctoral Dissertations
In recent years, Condition Monitoring (CM), which can be performed via several sensor channels, has been recognized as an effective paradigm for failure prevention of operational equipment or processes. However, the complexity caused by asynchronous data collection with different and/or time-varying sampling/transmission rates has long been a hindrance in the effective use of multichannel data in constructing empirical models. The problem becomes more challenging when sensor readings are incomplete. Traditional sensor data recovery techniques are often prohibited in asynchronous CM environments, not to mention sparse datasets. The proposed Functional Principal Component Analysis (FPCA) methodologies, e.g., nonparametric FPC model and semi-parametric …