The present work proposes a new computational algorithm for analyzing Morton Effect using a Successive Iterative Synchronous Response Algorithm (SISRA). Previous studies on the Morton Effect were based on Eigen or Nyquist analysis for stability studies and predicted only an onset speed of instability. The outcome of SISRA is the convergence of response to a steady state orbit in a finite number of iterations. A progressive increase in the response with increasing running speed indicates the former instability. SISRA predicts both the synchronous response for the speed range of concern plus the speed where the response becomes divergent. SISRA is implemented in a Timochenko-beam-based finite-element rotordynamics software suite. SISRA analyzes the Morton Effect as a synchronous response problem with excitations from: (1) mechanical imbalance, (2) induced thermal bent shaft moments, and (3) mechanical imbalance that is induced by thermal bow. A general elliptical orbit can be decomposed into the sum of forward and backward circular orbits. As input, SISRA requires that, at a specified speed, equilibrium position, and orbit: (1) the predicted maximum differential temperature, and (2) the angle between hot spot (position of maximum temperature) and position of minimum film thickness. Two examples from the published literature are considered. SISRA predicted higher vibration levels, even before the motion diverges due to Morton Effect. In some cases, the synchronous response of the system due to Morton Effect is orders of magnitude greater than the response due only to mechanical imbalance. The combined effects of: (1) mechanical imbalance with induced thermal bent shaft moments, and (2) mechanical imbalance with thermally induced mechanical imbalance are also studied. The impact of induced thermal bent shaft moments is found to be greater than the mechanical imbalance induced by thermal bow. A parametric investigation on the impact of the changes of (1) bearing length to diameter ratio, (2) reduced viscosity of the lubricant, (3) bearing radial clearance to radius ratio and (4) overhung mass magnitude is performed to consider their respective impacts on synchronous response. Based on the available input data and the cases considered, reducing viscosity and reducing the overhung mass are found to be the best remedies to alleviate problems arising from the Morton Effect.

In this thesis, the dynamic responses of harmonic drive (H.D.) systems under different operating conditions are investigated. The numerical simulation and the experimental measurements of harmonic drive systems are included in this thesis. The effects of flexspline of harmonic drive, i.e., the torsional stiffness and the damping ratio on the response of corresponding system are studied .Lagrange¡¦s equation is employed to derive the equation of motion of the system. The system equation with a nonlinear torsional stiffness is solved by using the 6th order Runge-Kutta method. Comparison between numerical simulation results and experimental measured data indicate that the proposed harmonic drive model is accurate and feasible for simulating the dynamic response of a harmonic drive system.

Abstract The harmonic drive mechanism has been used wildly in industrial robots. High reduction ratio, few components, and quiet torque transfer are the advantages of this device. In this thesis, the dynamic characteristic of an integrated DC motor and harmonic driver system is investigated. The dynamic equations of the harmonic drive systems are derived by applying Lagrange¡¦s equation. Two different harmonic driver designs, i.e. a cup-type with two teeth difference and a circular type with four teeth difference are used in the analysis. The system responses are simulated by employing the sixth order Runge-Kutta method. Comparison between numerical simulation results and experimental results, it indicates that the proposed model is feasible and accurate for simulating the dynamic response of an electro-mechanical integrated harmonic drive system.

Every time emergency responders respond to an incident, they enter an ambiguous situation that is an ill-defined problem space. As the responders engage with the incident, they discover, piece by piece, the unique interlocking problems and act quickly to put form and structure onto the potential solution. In order to quickly, effectively, and safely resolve an incident, emergency responders must have depth and breadth of knowledge across responder disciplines and domains. This knowledge is acquired through both formal training courses and informal training in the station house. The ability to quickly assess a situation, accurately identify the elements as they emerge and their significance, then decide on a course of action combining a variety of domains and skill sets speaks to the creative nature of emergency responders. This study uses naturalistic inquiry to explore what it is like to be an emergency responder, describe how creativity manifests itself in a field environment, and discuss what emergency responders want in their training. This study found that being an emergency responder is emotional, exciting, stressful, challenging, full of the unexpected, and rewarding. During an incident, emergency responders are dealing with the complex interactions of various emotions while resolving difficult and often sad situations. Being an emergency responder is synonymous with being a good problem solver; they are also highly emotionally resilient. The process of creativity within an emergency response environment is seen through preparation that is, training. The consistent review and development of skills makes the skills automatic. Responders also cross-train and, often, an individual responder will have expertise in multiple areas. The improvisational skills of emergency responders to events which are often emergent and creative in their own right, demonstrate a depth of creative force through the handling of complex, high-risk situations with persistence, endurance, and determination. Finally, this study found that emergency responders are passionate about their training. They know that what they learn and practice during training evolutions forms the foundation of their professionalism, provides opportunities to learn new skills or hone already established skills, reinforces safety considerations, and will save their lives and the lives of other people.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI/Dissertation Abstracts International.

Thesis (M.S.M.E.)--University of Massachusetts Amherst, 2009. / Open access. Includes bibliographical references (p. 91-95).

Thesis--Brandeis University. / eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 122-133.

Thesis--University of Florida, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 45-46.

Thesis (Ph. D.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains vii, 74 p. : ill. Includes abstract. Includes bibliographical references (p. 72-74).

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 167-178). Available also in a digital version from Dissertation Abstracts.