ABSTRACT PEEK matrix reinforced by carbon fibers as one thermoplastic composite material is studied. Thermoplastic composites have the advantages of high specific stiffness and strength, longer fatigue life, good resistance to moisture absorption and high temperature condition. The thesis is aimed to investigate the mechanical properties and fracture mechanism of the centrally notched AS-4/PEEK composite laminates subjected to tension-tension fatigue loading at elevated temperature. We use three common types of laminates, such as cross-ply , quasi-isotropic and angle-ply . After centrally notched, we first obtain the base-line data of mechanical properties by tensile tests at five different temperatures, such as 25¢J¡B75¢J¡B100¢J¡B125¢J¡B150¢J. Then, the fatigue tests are conducted, we receive the fatigue strength and life and establish the stress-life curves. The fatigue characteristics and fracture mechanism of a centrally notched composite laminate at elevated temperature are also recorded and observed. The empirical results can be concluded as follows. At the same temperature, the laminate of cross-ply possesses the largest ultimate strength and fatigue strength, quasi-isotropic the second angle-ply the smallest. As for the elastic modulus, the laminate of cross-ply is larger than that of quasi-isotropic. However, the large strain of angle-ply is within the plastic range that is out of the limit of the study. Thus, a further investigation is needed for angle-ply laminates alone. After centrally notched, the net area is reduced of the specimen, and then the elastic modulus is raised and the ultimate strength and fatigue strength of composite materials are lower. As the temperature increasing, the ultimate strength, fatigue strength and elastic modulus are all decreasing.

Surface Laser Light Scattering (SLLS) is a heterodyne detection technique used to probe the surface properties of fluid interfaces. These interfaces are either liquid/liquid or vapor/liquid, and they may include insoluble monolayers or polymer films deposited on liquid surfaces as well as microemulsions in solution at low concentration. This technique provides one with a nonperturbative way to obtain surface tension and viscosity. A diffraction grating is employed to provide a stable local oscillatior, hence selecting an accurate ripplon wave vector . This thesis deals with the investigation of the interface between air and solution consisting of the methanol and water mixture and poly(N-isopropylacrylamide) or PNIPAM which is one of the fascinating polymeric materials. The polymer PNIPAM shows distinct responses to variations in the surrounding environment (such as thermal gradient, change in pH, etc.). The surface tension extracted from the SLLS data using the Kelvin equation is found to agree well with that obtained by using the Wilhelmy plate method. For the range of wave vectors cm-1, the power spectrum detected in frequency domain can be fit to a Lorentzian profile. Our experiments show that when the volume percentage of methanol increases, the interfacial property becomes insensitive to the presence of PNIPAM.

Abstract The occurrence of ripples on the workpiece surface after solidification in electron-beam weld or melting is experimentally and analytically investigated. The maximum accelerating voltage and welding current of electron-beam welder are 60kV and 50mA, respectively, while the workpieces are four different materials containing different quantities of sulfur. Using a scale analysis to account for heat transfer and fluid flow induced by different quantities of surface active element in the molten pool. The result predicted results show good agreement with experimental data.

This thesis presents the design and implementation of a generative model of tonal tension. It further describes the application of the generative model in realtime sonification. The thesis discusses related theoretical work in musical fields including generative system design, sonification, and perception and cognition. It highlights a review of the related research from historical to contemporary work. It contextualizes this work in informing the design and application of the generative model of tonal tension. The thesis concludes by presenting a formal evaluation of the system. The evaluation consists of two independent subject-response studies assessing the effectiveness of the generative system to create tonal tension and map it to visual parameters in sonification.

Thèse de doctorat : sciences. Génie électrique : Ecully, Ecole centrale de Lyon : 2005. / 158 réf.

Thèse doctorat : Génie Electrique : Villeurbanne, INSA : 2004. / Titre provenant de l'écran-titre. Bibliogr. p. [191]-197.

Thèse de doctorat : sciences. Génie électrique : Ecully, Ecole centrale de Lyon : 2005. / Titre provenant de l'écran-titre. 158 réf.

Reproduction de : Thèse de doctorat : Mathématiques : Lyon 1 : 2002. / Titre provenant de l'écran titre. 68 réf. bibliogr.

Reproduction de : Thèse doctorat : Génie électrique : Pau : 2008. / Titre provenant de l'écran titre.

Thèse de doctorat : Électronique : Lille 1 : 2002. / N° d'ordre (Lille) : 3184. Résumé en français et en anglais. Bibliogr. f. 125-131.