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Model Identification, Updating, And Validation Of An Active Magnetic Bearing High-Speed Machining Spindle For Precision Machining Operation, Adam C. Wroblewski
Model Identification, Updating, And Validation Of An Active Magnetic Bearing High-Speed Machining Spindle For Precision Machining Operation, Adam C. Wroblewski
ETD Archive
High-Speed Machining (HSM) spindles equipped with Active Magnetic Bearings (AMBs) are envisioned to be capable of autonomous self-identification and performance self-optimization for stable high-speed and high quality machining operation. High-speed machining requires carefully selected parameters for reliable and optimal machining performance. For this reason, the accuracy of the spindle model in terms of physical and dynamic properties is essential to substantiate confidence in its predictive aptitude for subsequent analyses.This dissertation addresses system identification, open-loop model development and updating, and closed-loop model validation. System identification was performed in situ utilizing the existing AMB hardware. A simplified, nominal open-loop rotor model was …
Modeling And Performance Investigation Of A Rotor With Dissimilar Bearing Support System, Yunlu Li
Modeling And Performance Investigation Of A Rotor With Dissimilar Bearing Support System, Yunlu Li
ETD Archive
Different types of bearings have different dynamic characteristics. By using one type of bearing at one end of a rotor and another type of bearing at the other end of the rotor, it is possible to exploit the advantages of both types in the same system. One example of such combination is a bronze bushing and active magnetic bearing (AMB). In the available literature, there are examples of such systems but are not fully explored with regard to how to model the system to fully utilize both support type properties. This thesis investigates the modeling and performance of such a …
Identification Of Unmodeled Dynamics In Rotor Systems Using Mu-Synthesis Approach, Ryan J. Madden
Identification Of Unmodeled Dynamics In Rotor Systems Using Mu-Synthesis Approach, Ryan J. Madden
ETD Archive
It is well recognized that analytical models only approximate the true dynamics of analyzed rotating machines, due to the presence of components that are inherently difficult to model. Such models of rotating machines are driven by the best engineering knowledge and experience, and very often are updated based on experimental results. The problem of unmodeled or missing dynamics can be exacerbated in the presence of rotor structural damage such as a transverse crack on a shaft. This thesis will present an effective approach for model updating using advanced tools developed in robust control theory, specifically mu-synthesis. The methodology will be …
Dynamic Analysis Of A Rotor Bearing System, Sandi Elhibir
Dynamic Analysis Of A Rotor Bearing System, Sandi Elhibir
ETD Archive
This thesis presents the results of the finite element analysis (FEA) approach for designing a Permanent Magnet Alternator (PMA). The PMA is configured as a cantilever hollow shaft supported by two identical rolling contact bearings. The performance requirements of the PMA are a maximum operating speed of 16,000 rpm, with a maximum shaft displacement of less than 0.010 in at its free end. The static and dynamic results of a cantilever beam was predicted by closed form solutions and verified to those results obtained from FEA for code validation. A mathematical model of a rotor-bearing system was proposed and analyzed …
Development Of Effective Balancing Procedure For Ct Scanner, Jeremy David Pettinato
Development Of Effective Balancing Procedure For Ct Scanner, Jeremy David Pettinato
ETD Archive
Since the beginning of medical organizations, engineering departments have introduced new innovative ideas and designs to advance image quality. In the case of a CT scanner, one of the largest and most cost effective ways to achieve superior image quality is through a well balanced rotating array. The focus of this thesis is the development of a balancing procedure which will effectively balance a CT scanner rotating array. Rigid rotor (dynamic) balancing techniques are utilized in order to balance the Philips CT scanner rotor. Upon completion of the dynamic balancing of the CT scanner rotor a new an innovative way …
Health Monitoring Of Cracked Rotor Systems Using External Excitation Techniques, Adam C. Wróblewski
Health Monitoring Of Cracked Rotor Systems Using External Excitation Techniques, Adam C. Wróblewski
ETD Archive
Cracked rotors present a significant safety and loss hazard in nearly every application of modern turbomachinery. This thesis focuses on the health monitoring, modeling, and analysis of machines with transverse breathing cracks, which open and close due to the self-weight of the rotor. After considering the modeling of cracked rotors, the thesis investigates an active structural health monitoring approach, focusing on the application of an active magnetic actuator to apply a specially designed external force excitation to the rotating shaft. Extensive experimental data has been collected and analyzed utilizing advanced diagnostic techniques. The presented results demonstrate that the use of …