The implementation of high-speed passenger trains (HST) within existing highway right-of-way (ROW) offers a solution for regions with a demand for the capacity and service offered by HST but lacking the support for sharing freight rail ROW or acquiring new ROW corridors. The states of Florida, Colorado, California and Nevada propose to use highway ROW for their HST projects to increase the capacity of the corridor, prevent or minimize impacts and prevent disruption of freight rail operations. Despite the constraints of using existing highway ROW, such as speed-limiting degrees of curvature and safety concerns, solutions and mitigation measures exist. The purpose of this thesis is to present the HST projects in the United States proposing use of highway ROW, the potential benefits and engineering issues to consider and the feasibility of using the existing I-35 ROW in Texas for HST. / text

published_or_final_version / Politics and Public Administration / Master / Master of Public Administration

Lau Yiu Kee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 142-146). / Abstracts in English and Chinese. / LIST OF TABLES --- p.viii / LIST OF FIGURES --- p.x / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Railway Vehicle Suspension --- p.2 / Chapter 1.3 --- Semi-Active Magnetorheological Fluid Damper --- p.3 / Chapter 1.4 --- Research Objectives --- p.4 / Chapter 1.5 --- Thesis Outline --- p.5 / Chapter 2. --- BACKGROUND --- p.7 / Chapter 2.1 --- MR Fluids --- p.7 / Chapter 2.1.1 --- Composition of MR fluids --- p.7 / Chapter 2.1.2 --- Properties and characteristics of MR fluids --- p.8 / Chapter 2.1.3 --- Literature review --- p.13 / Chapter 2.2 --- MR Devices --- p.13 / Chapter 2.2.1 --- Advantages of MR devices --- p.13 / Chapter 2.2.2 --- Common device geometries --- p.14 / Chapter 2.2.3 --- MR fluid based applications --- p.15 / Chapter 2.2.4 --- Literature review --- p.19 / Chapter 2.3 --- Overview of Railway Vehicles --- p.21 / Chapter 2.3.1 --- "Passive, active and semi-active suspensions" --- p.21 / Chapter 2.3.2 --- Basic railway vehicle structure --- p.23 / Chapter 2.3.3 --- Literature review --- p.25 / Chapter 2.4 --- Railway Vehicle Suspension Systems --- p.25 / Chapter 2.4.1 --- Primary vertical suspension --- p.25 / Chapter 2.4.2 --- Secondary vertical suspension --- p.27 / Chapter 2.4.3 --- Secondary lateral suspension --- p.27 / Chapter 2.4.4 --- Yaw suspension --- p.28 / Chapter 3. --- DESIGN CONSIDERATIONS FOR MR DAMPERS --- p.29 / Chapter 3.1 --- Overview of Existing MR Dampers --- p.29 / Chapter 3.1.1 --- Monotube MR fluid damper --- p.29 / Chapter 3.1.2 --- Double-ended MR damper --- p.31 / Chapter 3.1.3 --- Bellow type MR damper --- p.35 / Chapter 3.2 --- Optimal Design and Configuration of Magnetic Circuit --- p.35 / Chapter 3.2.1 --- Magnetic circuit and magnetic field orientation --- p.35 / Chapter 3.2.2 --- Physical dimension of MR damper --- p.38 / Chapter 3.2.3 --- Connection polarity of electromagnetic circuit --- p.40 / Chapter 3.3 --- Basic Geometry Design Considerations --- p.43 / Chapter 3.3.1 --- Controllable force and dynamic range --- p.43 / Chapter 3.3.2 --- Geometry constraints --- p.45 / Chapter 3.3.3 --- Magnetic circuit design --- p.47 / Chapter 4. --- DEVELOPMENT AND FABRICATION OF MR DAMPERS --- p.51 / Chapter 4.1 --- Pneumatic Air Cylinder --- p.51 / Chapter 4.2 --- Fabrication Process of Double-Ended MR Dampers --- p.55 / Chapter 4.2.1 --- Modifications on the pneumatic air cylinder --- p.55 / Chapter 4.2.2 --- Manufacturing processes of the piston sleeve --- p.56 / Chapter 4.2.3 --- Modification processes of the original piston rod --- p.59 / Chapter 4.2.4 --- Modification of the piston staging area --- p.60 / Chapter 4.2.5 --- Copper wire wrapping and damper assembling --- p.63 / Chapter 5. --- EXPERIMENTAL SETUP AND RESULTS --- p.66 / Chapter 5.1 --- Experimental Setup for the Double-Ended MR Damper --- p.66 / Chapter 5.1.1 --- Instron 8801 loading machine --- p.66 / Chapter 5.1.2 --- Experimental setup for testing the MR damper --- p.67 / Chapter 5.2 --- Force-Lag Phenomenon of MR Damper --- p.70 / Chapter 5.2.1 --- Force-lag phenomenon --- p.70 / Chapter 5.2.2 --- Reasons of the force-lag phenomenon --- p.73 / Chapter 5.2.3 --- Methods to eliminate the force-lag phenomenon --- p.76 / Chapter 5.2.4 --- Setup for hydraulic pump system --- p.77 / Chapter 5.2.5 --- Results and effects of the pressurized MR damper --- p.79 / Chapter 5.3 --- Experimental Results for Testing the MR Damper --- p.83 / Chapter 6. --- SIMULATION RESULTS OF SEMI-ACTIVE TRAIN SUSPENSION --- p.87 / Chapter 6.1 --- MR Damper Model --- p.87 / Chapter 6.2 --- Rail Vehicle Model --- p.92 / Chapter 6.3 --- Semi-Active Railway Suspension --- p.94 / Chapter 6.3.1 --- Lateral vibration on the train --- p.94 / Chapter 6.3.2 --- Semi-active control strategy --- p.95 / Chapter 6.4 --- Simulation Results --- p.98 / Chapter 6.4.1 --- Lower sway mode excitation --- p.99 / Chapter 6.4.2 --- Upper sway mode excitation --- p.105 / Chapter 6.4.3 --- Mixed sway mode excitation --- p.110 / Chapter 6.4.4 --- BR high speed assault course --- p.116 / Chapter 6.4.5 --- Discussions --- p.124 / Chapter 6.5 --- Effects of Vibration on Ride Comfort --- p.128 / Chapter 7. --- CONCLUSIONS --- p.134 / APPENDIX --- p.136 / BIBLIOGRAPHY --- p.142

This thesis studies the dynamic model and simulation of a Half-Toroidal (HT) type Continuously Variable Unit (CVU) integrated into a conventional powertrain. A simplified parametric model of a HT-CVU is constructed using Finite Element Method (FEM) in which the continuous variable speed unit is discretized into lumped masses, spring and damper elements. Linearized Finite Elements (FE) have been used to model the contacts between the toroids and rollers. The phenomenon of slip and spin associated with the rolling-slipping contacts of the traction drives are modelled kinematically. All Finite Elements including the CVU model are integrated into the complete powertrain system. Free Vibration Analysis (FVA) of the multi degree of freedom system is carried out for torsional vibration for High Gear (HGR) and Low Gear Ratio (LGR) conditions. Further, FVA is carried out with a lock-up clutch engaged at high speed range. The results of the FVA indicates significant changes in natural frequencies and corresponding mode shapes for both HGR and LGR condition with a change in HT-CVU gear ratios. Change in natural frequencies and mode shapes for both HGR and LGR conditions are also observed for varying contact torsional stiffness. The change is significant till a certain value of contact torsional stiffness. Further increase in contact torsional stiffness within the HT-CVU does not affect the natural frequencies and corresponding mode shapes significantly. The results of the modal analysis carried out for a HT-CVU integrated powertrain with a lock-up clutch engaged at high speed range illustrates the ability of the lock-up clutch to simultaneously suspend engine and roller element excitation. However, for certain natural frequencies the modal analysis of the integrated powertrain system indicates suspension of engine and input toroid but increased excitation for the roller element of the HT-CVU. The transient dynamic analysis is carried out to understand the behaviour of the CVU integrated into the complete powertrain and to identify and possibly correct potential problems associated with the system. The simulation is carried out for constant and variable throttle conditions for the powertrain with and without a lock up clutch engaged at high speed ranges. A piecewise curved gear ratio map is assumed for all conditions. All analyses are carried out for throttle 'tip-in' condition. The results of the transient dynamic analysis indicate that the transient responses of input and output rollers of the HT-CVU exist when clutch change occurs during vehicle acceleration period from stand still condition. The clutch change also leads to disturbances in the HT-CVU output torque to driveline and in vehicle speed. This leads to imperfect drive feel for the driver. The simulated vehicle velocity indicates powerful acceleration characteristics of the HT-CVU integrated powertrain. Engine harmonics is modelled as a rich collection of various forcing frequencies. These frequencies impress on the response of both the roller and output toroid and are observed in the simulation. Stability analysis is carried out on the powertrain to understand the effect of damping in the tyres and damping within the HT-CVU on the stability of the powertrain. Severe or even unstable response of the HT-CVU takes place if the damping in the HT-CVU and/or the tyres is insufficient during the initial acceleration period and later after the clutch change occurs and when the vehicle is at high speeds. The results of the stability analysis lead us to reason with confidence that the tyre and HT-CVU damping have an effect on the dynamic characteristics and the stability of the system. The response of the powertrain becomes stable when a lock-up clutch is applied over the high speed ranges even if the damping in the tyres remains insufficient. The modal damping ratios for stable and unstable conditions are also discussed. Future investigations need to be carried out in order to understand in depth the fluid-metal interaction in the HT-CVU. This can be achieved by modelling in non-linear drag torque which would act on the HT-CVU elements.

Mémoire IEP : Science politique : Grenoble, IEP : 2006. / Séminaire : "Politique et Environnement" sous la direction de Stéphane La Branche. Titre provenant de la page de titre numérisée. Bibliogr. p. 126-127.

Positioning systems for trains are traditionally based on track-side infrastructure, implying costs for both installation and maintenance. A reliable on-board system would therefore be attractive. Sufficient reliability for on-board systems is likely going to require a multi-sensor solution. This thesis investigates how measurements from bogie-mounted inertial and magnetic sensors can contribute to such a system. The first part introduces and compares two different methods for estimating the speed. The first one estimates the fundamental frequency of the variations in the magnetic field, and the second one analyses the mechanical vibrations using the accelerometer and gyro, where one mode is due to the wheel irregularities. The second part introduces and evaluates a method for train localization using magnetic signatures. The method is evaluated both as a solution for localization along a given track and at switchways. Overall, the results in both parts show that bogie-mounted inertial and magnetic sensors provide accurate estimates of both speed (within 0.5 m/s typically) and location (3-5 m accuracy typically).

The primary objective of this research is to develop a visual design process for gear trains with multiple stages of reduction and varying configurational architectures. One of the main challenges in the design of such gear trains is in the sizing of the individual gears such that high levels of performance are obtained in spite of constraints due to different gear configurations. Formal design procedures that successfully meet this challenge are developed. A key contribution of this research is the utilization of these design procedures to create sets of three-dimensional design maps. The design procedures help a designer manage more than 20 design parameters in designing for a broad range of gear train requirements (Rated torque capacity, Volume, Weight, Inertia, Responsiveness, Torque Density etc.) while accounting for assembly constraints. Each set of design maps corresponds to a given set of design parameters, some of which are held fixed and some of which are put in the hands of the designer. The latter set of design parameters are termed in this research as design knobs. They can be ‘tuned’ by a designer in order to generate new sets of design maps. The idea is that a designer, using the design information conveyed to him/her graphically through a given set of design maps, is able to then tune the design knobs to generate an updated set of design maps which reflect design solutions that are more desirable in terms of the application requirements. By adjusting the design knobs and looking at updated design maps, a designer is able to quickly assess the effect of his/her design decisions. The end result is that a single designer is empowered with the ability to quickly arrive at a preliminary design of a gear train that satisfies the design requirements. This preliminary design would be a good starting point for more detailed design development. / text

No description available.

This thesis studies the dynamic model and simulation of a Half-Toroidal (HT) type Continuously Variable Unit (CVU) integrated into a conventional powertrain. A simplified parametric model of a HT-CVU is constructed using Finite Element Method (FEM) in which the continuous variable speed unit is discretized into lumped masses, spring and damper elements. Linearized Finite Elements (FE) have been used to model the contacts between the toroids and rollers. The phenomenon of slip and spin associated with the rolling-slipping contacts of the traction drives are modelled kinematically. All Finite Elements including the CVU model are integrated into the complete powertrain system. Free Vibration Analysis (FVA) of the multi degree of freedom system is carried out for torsional vibration for High Gear (HGR) and Low Gear Ratio (LGR) conditions. Further, FVA is carried out with a lock-up clutch engaged at high speed range. The results of the FVA indicates significant changes in natural frequencies and corresponding mode shapes for both HGR and LGR condition with a change in HT-CVU gear ratios. Change in natural frequencies and mode shapes for both HGR and LGR conditions are also observed for varying contact torsional stiffness. The change is significant till a certain value of contact torsional stiffness. Further increase in contact torsional stiffness within the HT-CVU does not affect the natural frequencies and corresponding mode shapes significantly. The results of the modal analysis carried out for a HT-CVU integrated powertrain with a lock-up clutch engaged at high speed range illustrates the ability of the lock-up clutch to simultaneously suspend engine and roller element excitation. However, for certain natural frequencies the modal analysis of the integrated powertrain system indicates suspension of engine and input toroid but increased excitation for the roller element of the HT-CVU. The transient dynamic analysis is carried out to understand the behaviour of the CVU integrated into the complete powertrain and to identify and possibly correct potential problems associated with the system. The simulation is carried out for constant and variable throttle conditions for the powertrain with and without a lock up clutch engaged at high speed ranges. A piecewise curved gear ratio map is assumed for all conditions. All analyses are carried out for throttle 'tip-in' condition. The results of the transient dynamic analysis indicate that the transient responses of input and output rollers of the HT-CVU exist when clutch change occurs during vehicle acceleration period from stand still condition. The clutch change also leads to disturbances in the HT-CVU output torque to driveline and in vehicle speed. This leads to imperfect drive feel for the driver. The simulated vehicle velocity indicates powerful acceleration characteristics of the HT-CVU integrated powertrain. Engine harmonics is modelled as a rich collection of various forcing frequencies. These frequencies impress on the response of both the roller and output toroid and are observed in the simulation. Stability analysis is carried out on the powertrain to understand the effect of damping in the tyres and damping within the HT-CVU on the stability of the powertrain. Severe or even unstable response of the HT-CVU takes place if the damping in the HT-CVU and/or the tyres is insufficient during the initial acceleration period and later after the clutch change occurs and when the vehicle is at high speeds. The results of the stability analysis lead us to reason with confidence that the tyre and HT-CVU damping have an effect on the dynamic characteristics and the stability of the system. The response of the powertrain becomes stable when a lock-up clutch is applied over the high speed ranges even if the damping in the tyres remains insufficient. The modal damping ratios for stable and unstable conditions are also discussed. Future investigations need to be carried out in order to understand in depth the fluid-metal interaction in the HT-CVU. This can be achieved by modelling in non-linear drag torque which would act on the HT-CVU elements.

Thesis (M Arch)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: John Brittingham. Includes bibliographical references (leaves 63-69).