This thesis is concerned with the free vibration analysis of stiffened circular cylindrical and conical shells. The study was carried out with a view to improving the accuracy and efficieny of various modelling techniques for the prediction of the stiffened shells natural frequencies and mode shapes. A review of the existing literature covering various aspects of the shell vibrations problem and modelling techniques has been given at the beginning of each chapter with a critical appraisal of the assumptions made and results obtained. Initially the continuum energy approach was used for the analysis. The developed method allows for discrete consideration of stiffeners having arbitrary location and properties. Energy of bending in two planes and rotary inertia have been included in the analysis. Various types of stiffened shells with shear diaphragm ends condition were analysed using this method for the prediction of their natural frequencies. The predicted results have been compared with published experimental results. The finite element technique was also used for the prediction of natural frequencies and mode shapes of stiffened shells. Axisymmetric shell of revolution element, Facet shell element, semi-100f element and various types of beam elements, which are available within the PAFEC 75 suite of programs, were used for these studies. An efficient modelling technique has been introduced for ring stiffened cylindrical and conical shells by the use of the shell of revolution element. For improved accuracy of the predicted frequencies and a more economical model, shell symmetry was utilized for the free vibration analysis of unstiffened and stiffened shells. Half, quarter and one eighth models were studied by developing the appropriate boundary conditions and are discussed here. The free vibration characteristics of orthogonally stiffened cylindrical shells and an orthogonally stiffened cylindrical panel have been studied. An eight noded stiffened super shell element was developed for this study. This element was used for modelling various other types of stiffened shells and the predicted natural frequencies have been compared with known published experimental and theoretical results. Experimental verification of theoretical predictions of natural frequencies and mode shapes of an orthogonally stiffened cylindrical panel was carried out and is reported here.

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The most important areas of interest concerning air cored linear machines (ACLM), their design, development and application to guided ground transportation are presented. A description of the origins of high speed guided ground transportation (HSGGT) is given which covers tracked air cushion vehicle and linear induction motor development, as well as the electromagnetic and electrodynamic systems of levitation. ACLM began as the favoured propulsion option for the electrodynamic system, and the machine characteristics of the linear synchronous motor (LSM) are discussed with optimization techniques given for choice of wavelength. Stress factors for rectangular coils with tight corner radii can be calculated using a circular coil equivalent. The linear commutator motor (LCM) provides a means of achieving high local track power density without degrading overall machine performance. Several forms are examined and the trade off and comparison with LSM made. The system comparison of the electrodynamic and electromagnetic systems (EDS and EMS) of magnetic levitation indicates that specifying Just lift to drag ratio and specific energy Intensity is an insufficient base. Comparison is made of the German EMS and EDS designs, together with a comparison of other groups' EDS vehicles. The German EDS design is found to be heavily penalised by excessive low speed suspension weight. Several variations of a new type of ACLM using on board flux pumping are proposed. The advantages are that a passive track structure is possible, and a cryogenically cooled winding can be used as a cost effective alternative to a superconducting coll. Application of ACLM to propulsion of advanced duorail vehicles is set out together with the possibility of speed extension with reduced track wear and Initial capital coat, as well as reduced manning and maintenance cost. An Advanced Passenger Train with LSM would appear to be a feasible option for future transport needs, and extension to a low speed urban vehicle using for example liquid nitrogen cooled pool boiling coils would similarly present a low cost system. An indexed bibliography containing over 400 HSGGT references is included, with a bias to EDS and ACLM.

Greater demands are being placed on the separable connector to perform with higher reliability in harsher automotive environments. Corrosion in its various forms is a major mechanism which affects contact reliability and this current work focuses on surface oxidation and the related phenomenon of fretting corrosion, from which hot dipped tin (HDT), a common automotive connector coating, is known to suffer. For an in-depth study of high contact resistance, in both static conditions and when subjected to relative micromovement, an interdisciplinary approach was necessary, drawing on the results of published work carried out in the fields of contact and surface science, corrosion and tribology.

The behaviour of trains used at high speeds for transporting men along mine railways is examined using a number of mathematical models. These models predict the responses of different rail vehicles to typical irregularities in the track, and are used to examine the guidance, the ride, and the likelihood of derailment of the main classes of manriding trains used in British coal mines. The outcome of the modelling compares favourably with the results of tests carried out on actual vehicles. The investigation has shown that the safe speed at which trains may operate is ultimately restricted by the condition of the track, but changes in the design of the vehicles can lead to an improved performance. The use of conventional wheelsets, for example, can reduce flange wear significantly and so allows higher speeds to be reached. Guidelines for the design of vehicles intended for high speed use are included in this thesis.

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This thesis introduces a versatile finite element package, which is tailored for the static and dynamic analysis of radial tyres. A new axisymmetric solid-of-revolution element which takes into consideration, large deformation, the influence of composite orthotropic material and the viscoelasticity and the nonlinearity of the material properties, has been developed for a general loaded tyre. The finite element package has been verified by comparing its results with available analytical, numerical and experimental results. A full static and dynamic investigation has been carried out for a commercial tyre 175 HR 14 and results obtained by using the package have been compared with available experimental results developed by DUNLOP or carried out at Cranfieid. The package has proved to be reliable, flexible, efficient, economic and accurate. The numerical instability problems which are prevalent in this type of analysis have been overcome by the derivation of a developed Newton-Raphson iterative scheme.

Even since railway vehicles were invented, railway scientists and engineers have been putting a lot of effort in finding the solution to the fundamental conflict between vehicle stability in the lateral plane and vehicle's capability of negotiating curves. Many configurations of railway bogie vehicles have been proposed and applied to minimise the conflict. The purpose of the research project is i) to create new configurations that can decouple the basic conflict, ii) to investigate dynamic behaviour of the new configurations and iii) to conceive a new mechanism that can improve the dynamics of the new configurations. Three configurations of body-steered bogie vehicles have been set up in the research. The sufficient conditions for them to be capable of perfect steering have been derived. They are called perfect steering vehicles when they satisfy these sufficient conditions. Their curving ability, stability and ride performance have been investigated. To overcome the disadvantages of the perfect steering vehicles, the reconfigurable mechanism has been conceived. The improvement in the dynamic behaviour of the perfect steering vehicles with the reconfigurable mechanism has been demonstrated. A computer program has been developed to undertake the simulation. The steering capability of the perfect steering vehicles is much better than that of conventional bogie vehicles. There are two modes of instability in the perfect steering vehicles: low conicity instability and conventional instability in the perfect steering vehicle. The perfect steering vehicles can decouple the conflict between their conventional stability and curving. The improvement of stability and ride performance of the perfect steering vehicles is, however, limited by the low conicity instability. When the reconfigurable mechanism is applied, a body-steered bogie vehicle can become a perfect steering vehicle when on curves and can become a conventional bogie vehicle when in other circumstances. Low conicity instability can be eliminated when the reconfigurable mechanism is used. This class of vehicles possess the advantages of both conventional bogie vehicles and perfect steering vehicles, and thus, provide a very valuable solution for the fundamental conflicts between the stability and steering ability and between ride performance and stability of railway vehicles. The findings in this thesis have great significance in developing perfect steering vehicles.

Environmental legislation is driving research into new technologies for future automotive products. Electric vehicle technologies have the potential to meet these legislative requirements, but are currently restricted by cost implications. This work focuses on the potential for offsetting this cost against potential benefits of the technology. In particular, the application of a motor at each wheel, facilitating Independent Wheel Control (IWC). A scale model vehicle is incorporated into a Hardware-in-the-Loop (HIL) simulation for the application of developing IWC strategies. The model uses four motors, each driving a single wheel in order to effect this control. Control strategies are 'rapid prototyped' in MathWorks Simulink™ using an industrial standard tool, dSPACE™, to operate the strategies in real-time HIL simulation. The application of a control strategy, representative of a conventional 4x4 behaviour, incorporating a lockable centre differential is applied. Shaft compliance is modelled in order to provide a test of the system operation with a transient dynamic response. Stability issues raised through this application are related to signal processing. An estimator is devised in software to overcome these issues, producing a stable system response. The work concludes that the use of a physical scale model for the development of IWC strategies is inappropriate in the context of supporting the development of a full-scale vehicle due to the complexity of reproducing a scaled tyre. However, in a broader sense, the approach of utilising a physical model has demonstrated significant benefits in promoting the concept of lWC within an industrial organisation, and in assisting product development.

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