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In this thesis, detonation limits in small diameter tubes are investigated to further the understanding of the near limit detonation phenomenon. Mixtures with argon dilution (stable detonation) and without dilution (unstable detonation) are used in the experiments. For stable mixture highly diluted with argon where instabilities are not the important propagation mechanism, failure can be attributed to losses to the tube wall. For the stable mixture, the limits obtained experimentally are found to be in good agreement with a quasi-one dimensional ZND theory with flow divergence and have curvature due to boundary layer displacement effect. For detonations in undiluted mixtures (unstable) where instabilities are the principal propagation mechanism, agreement between experiments and ZND theory is not good. For unstable detonations suppression of the instabilities of the cellular detonation due to boundary conditions are thought to be responsible for the failure of the detonation wave. Different near-limit propagation regimes are also observed, e.g. spinning, galloping, stuttering, etc. Based on the present experimental results, an attempt is made to develop an operational criterion for the propagation limits of stable and unstable detonations. / Cette étude a pour but d'étudier les limites de propagation de détonations dans de très petits diamètres de tubes. Dans cette recherche, des mélanges hautement dilués avec de l'argon (stables) et des mélanges non-dilués avec de l'argon (instables) sont utilisés. Pour le mélange hautement dilué avec de l'argon, dans lequel les instabilités ne sont pas très présentes et dans lequel l'atténuation de la propagation de la détonation est principalement causée par les pertes de chaleur à la parois, la limite de détonation qui a été obtenue expérimentalement est en accord avec celle obtenue théoriquement par la résolution des équations quasi-stationnaires de la théorie ZND, où une divergence de l'écoulement simule les effets de couche limites à la paroi. Pour les détonations instables dans les mélanges non-dilués avec de l'argon, les régimes pour les différents modes de propagation près des limites de la détonation sont étudiés. Chacun de ces modes de propagation sont analysés attentivement afin de déterminer un critère pour définir les limites de propagation de détonations dans différents mélanges gazeux.

Planar parallel robot accuracy indices are evaluated because such robots are widely used in industrial applications where quick, precise positioning and alignment are essential. With their increasing use comes a need to develop a methodology to compare different parallel robot designs. However no simple method exists to adequately compare the accuracy of parallel robots. Certain indices have been used in the past such as dexterity, manipulability and global conditioning index, but they have inherent problems when applied to both translational and rotational motion of a parallel robot. In direct response to the need for more methods in evaluating the accuracy of parallel robots, this thesis presents a simple geometric method for computing the exact local maximum position error and maximum orientation error, given the actuator displacement inaccuracies. This new method gives a clear, quantitative way to evaluate planar parallel robots. This method is shown to work well when applied to a class of three-degree-of-freedom planar fully-parallel robots, whose legs each have each one passive revolute joint and two prismatic joints. / Les indices de précision d'un robot planaire parallèle sont analysés dans la présente thèse en raison de leur large utilisation dans des applications industrielles où la précision du positionnement et de l'alignement est essentielle. Leur utilisation croissante s'accompagne du besoin de développer une méthode pour évaluer différentes conceptions de robots parallèles. Cependant, il n'existe pas de méthode simple d'évaluation comparative de la précision des robots parallèles. Par le passé, on utilisait certains indices tels que la dextérité, la capacité de manipulation et l'évaluation globale, mais ces derniers présentaient des problèmes inhérents lorsque appliqués à la fois au mouvement de translation et de rotation d'un robot parallèle. En réponse directe au besoin de disposer de plus d'outils d'évaluation de la précision des robots parallèles, cette thèse présente une méthode géométrique simple pour calculer les inexactitudes maximales de positionnement et d'orientation, en tenant compte des inexactitudes de déplacement de l'actuateur.Il est prouvé que l'utilisation de cette nouvelle méthode est claire et quantitative pour l'évaluation de robots planaires parallèles. Elle donne de bons résultats quand on l'applique à une catégorie de robots planaires à trois degrés de liberté, dont les pattes ont chacune une a rticulation rotoïde passive et deux articulations prismatiques.

Achievement of high class surface finish is important to the high volume automotive industry when using the Resin Transfer Molding (RTM) process for exterior body panels. In this work, the effect of the fibre distribution in F3P preforms on the surface quality of RTM moulded panels was investigated. Taguchi experimental design techniques were employed to design test matrices and an optimization analysis was performed on the fibre preform architecture. The F3P preform fibre distribution was measured by carrying out image analysis of the light intensity transmitted through dry preforms. Test panels were manufactured using a flat plate steel mould mounted on a press. The panel surface quality was measured using the ONDULO non-contact surface measurement system. Fibre density distribution was compared to the measured surface roughness. Predicted surface quality is presented and compared to measured values from the manufactured parts. The results obtained indicate that small variations in preform fibre volume fraction and top veil thickness have no effect on the surface finish of 'Class A' composites parts. / Dans l'industrie automobile à haut taux de production, l'obtention d'un excellent fini de surface pour les panneaux extérieurs de carrosserie, fabriqués par le procédé d'injection sur renforts est très important. Dans ce travail, l'effet de la distribution des fibres de préformes F3P sur la qualité de panneaux moulés par le procédé d'injection sur renforts a été étudié. Un plan d'expérience basé sur la méthode de Taguchi a été employé pour concevoir la matrice de tests. L'architecture de la préforme a été aussi optimisée. La distribution des fibres des préformes F3P a été mesurée en performant une analyse d'image sur l'intensité lumineuse transmise à travers la préforme sèche. Des panneaux tests ont été fabriqués sur un moule d'acier monté sur une presse. La qualité de la surface des panneaux a été mesurée par un système de mesure sans contact appelé ONDULO. La distribution de la densité de fibre a été comparée à la mesure de rugosité des surfaces. La prédiction de la qualité des surfaces est présentée et comparée aux valeurs mesurées des panneaux tests. Les résultats obtenus indiquent qu'une petite variation de la fraction volumique de fibre ainsi que de l'épaisseur du voile supérieur n'a pas d'influence sur le fini de surface type A, de pièces composites.

In the present study, the influence of boundary conditions on the propagation of a vapor explosion in a stratified tin/water system has been investigated experimentally. In one of two experiments, a propagating interaction was initiated, by an exploding wire trigger, in a channel formed by two sections of 1.25 cm and 5 cm in width. The interaction failed consistently at the transition into the larger channel, due to the sudden lateral expansion. The behavior of the interaction was also investigated in the absence of confining walls, accomplished by triggering it in the center of a cylindrical tank. The system's response to the trigger varied erratically. Successfully triggered interactions travelled radially outward, about 5-11 cm from the center, at 30-60 m/s, producing overpressures of 0.15 to 0.5 MPa. The tin debris analysis indicated that only a thin layer of tin, ${ sim.86}$ mm deep, was involved in the interaction. This event is, however, suspected to be the result of an overdriven interaction, rather than a sustained propagation. The inherent difficulty in initiating a propagating interaction in the cylindrical geometry lies in the effect of the divergence of the flow. The energy yield/surface area of the event is of the same order of magnitude as that of single tin drop/water explosions and stratified tin/water interactions in a narrow channel, suggesting that the energetics are not significantly influenced by the geometry. This interaction, in many cases, served as a "precursor" event for a second, more energetic interaction, initiated in the coarse mixture of water and molten tin fragments lofted in the wake of the first interaction. (Abstract shortened by UMI.)

This thesis presents a novel approach in formulating kinematic constraints and a methodology for the dynamic modelling of mechanical systems with nonholonomic couplings. The method presented here is based on the natural orthogonal complement (NOC) of the kinematic constraint matrix associated with the linear homogeneous form of the kinematic constraints. The method of the NOC is used to model mechanical systems consisting of multiple-loop kinematic chains with nonholonomic constraints. Moreover, the method of the NOC, when coupled with an optimization technique, can be used for the feedforward control of redundantly actuated systems, as shown here. / The method of the NOC is first discussed in detail with the aid of an example of a two-wheeled mechanical system. Then, nonholonomic robotic mechanical systems, for example, automatic guided vehicles (AGVs), are analysed for simulation purposes. As a result, general-purpose software is developed for the kinematic and dynamic analyses of three-degree-of-freedom (3-DOF) AGVs. These AGVs use omnidirectional wheels which, in contrast to conventional wheels, e.g., the wheels in an automobile, result in 3-DOF motion of the vehicle. Isotropic designs of 3-DOF AGVs for direct kinematics are proposed, which should enhance the control of the vehicle. / With advanced computer graphics, a common trend is to use motion animation in assessing the time response of the systems under study. This brought about issues of algorithmic complexity that are inherent to motion animation. These issues are addressed with an example involving the attitude representation of a rigid body and the choice of a suitable coordinate frame in representing the dynamic equations of motion.

World wide steel consumption as grinding media is estimated at over 600,000 tons per annum. Total steel media wear in a given mill (ball or SAG) grinding process is a product of three recognized wear mechanisms---impact, abrasion, and corrosion of which the contribution of each wear mechanism to total media wear has not been well established. / A total media wear model can be defined on the assumption that the effect of each wear mechanism can be independently determined and this effect can be tied to mill charge motion as determined or estimated using a charge motion simulator, which allows for a total media wear model to be defined as the summation of the wear results of each mechanism. This necessitates the need for developing impact, abrasion and corrosion wear testers that will allow the study of media wear over a wide range of energy levels. Refinement of the impact test will allow studying how impact media wear at high energies behaves as a function of those energies. / This thesis research project work is focused on design and development of a high-energy impact wear tester. A comprehensive illustration on designing the newest version of the impact wear tester is explained in detail in order to exhibit how theoretical, virtual and experimental analyses could be integrated while designing a mechanical system.

A planar joint dyad consists of two rigid bodies connected by a P (prismatic) or R (revolute) joint and similarly connected to a fixed third body. The nature of the quadric constraint surface in the planar kinematic mapping image space is investigated. The geometric reasoning concerning why five points in the image space are sufficient to define an RR dyad and why four are enough to define the workspace of a PR or RP dyad is described, explained and exploited. / A general algorithm that combines both type and dimensional design synthesis to the planar joint dyad hence to the five-position Burmester problem in relation to planar four-bar mechanisms is presented. In addition, a special algorithm for the PR or RP dyad type selection is developed. It illustrates that PR or RP dyad can be typed and extracted from the general solutions. Moreover, the conditions under which five given poses admit 0, 2 or 4 real dyad solutions to the Burmester problem are explained. / In this thesis, examples which produce two RR dyad solutions and four dyad ones with various combinations of RR and PR pairs are presented to illustrate that the algorithm can be used to design planar four-bar mechanisms.

The structural behaviour of FRP-composite (E-glass/polyester) sheet pile panels subjected to uniform pressure load was investigated. Single, connected and concrete-filled 2.13 m panels were tested to failure with the objective of determining their moment capacity and failure mechanism. As the uniform load test procedure utilized in this study allowed for the prevention of premature local crushing behaviour within the span, the average moment capacity obtained in this study was more than double that found in prior studies of FRP sheet pile panels, averaging 11.15 kN.m in single panel tests and 9.32 kN.m in connected panel tests. Single panels exhibited little difference in moment capacity whether tested in the upright or inverted orientation and there was no apparent reduction in capacity when a single panel was subjected to repeated load cycles. Failure of both single and connected panels was generally attributable to local buckling and invariably occurred at a deflection of about 50mm, indicating that deflection limits may govern design. No joint failure was observed in connected panels. (Abstract shortened by UMI.)

The capability to perform dexterous operations in an autonomous manner would greatly enhance the productivity of space robotic operations. In the present thesis, we address this problem and propose a new methodology for vision-guided automatic grasping using SARAH, a three-fingered robotic hand. The Canadian Space Agency is planning to install SARAH on the International Space Station and we developed a methodology allowing this robotic hand to grasp objects autonomously by using a vision system in combination with an off-line grasp planner. / More specifically, a new algorithm for synthesizing force-closure grasps for planar and revolute objects with SARAH is formulated. The grasp synthesis explicitly takes into account the hand geometry constraints and optimizes several grasp quality criteria simultaneously. Subsequently, a vision-based approach for object pose identification is presented. A vision system incorporating a monocular camera mounted in the center of SARAH's palm was designed. Color information taken from a region of interest in the image and color indexing are used to locate the object in the scene. The virtual images predicting the appearance of the object are utilized for pose identification. The complete methodology is practical, ensures high quality grasps and provides an intuitive tool for automatic grasping. / Numerical results are presented for grasp synthesis of several objects with SARAH. These demonstrate the feasibility and optimality of the synthesized grasps, as well as the completeness and correctness of the methodology. Experiments were also conducted with SARAH as the end-effector of a 7-Degree-of-Freedom robot and vision-guided automatic grasping was achieved.