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Les hommes l'ont admiré et les femmes l'ont adoré. Alain Delon a eu le monde à ses pieds. René Clément, Luchino Visconti et Jean-Pierre Melville lui ont offert des rôles qui l'ont élevé au rang de mythe. Aujourd'hui, Delon est l'un des seuls acteurs français à pouvoir se targuer d'une renommée internationale. Il aurait pu abuser d'une photogénie exceptionnelle et se contenter de jouer les séducteurs virils. Au lieu de cela, Alain Delon a voulu cultiver le risque, être producteur, réaliser ses films et même devenir chef d'entreprise.

Coilable structures are thin-shell structures that can be coiled around a hub by flattening their cross-section. They are attractive for multiple space applications as they allow efficient packaging and deployment of large planar structures. Reducing the shell thickness enables smaller coiling radius and more efficient packaging. This thesis investigates TRAC structures, a type of coilable structure, made of ultra-thin composite materials. A design using a laminate made of glass fiber plainweave fabric and carbon fiber unidirectional tape is proposed, leading to a shell thickness of 0.08 mm. An in-autoclave, two-cure manufacturing process is presented, and a shape measurement method is used to mitigate post-cure shape changes due to residual stresses. A study of the structure behavior in its deployed configuration is performed. First, the behavior when subjected to pure bending is investigated experimentally for structures with a length of 575 mm. Two regimes are observed, with a pre-buckling phase transitioning to a stable post-buckling phase after an initial buckling event. The ultimate buckling moment following the stable post-buckling regime can be as high as four times the initial buckling moment. A finite element model is developed and is able to reproduce all the features observed experimentally, except the ultimate buckling. This simulation model is used to study the effect of varying the structure length from 300 mm to 5000 mm on the initial buckling moment. Results show that nonlinearities in the pre-buckling deformations of the flanges under compression lead to a constant wavelength lateral-torsional buckling mode for which the critical moment is mostly constant across the range of length. The torsional behavior of the TRAC structure is also investigated. Good agreement is obtained between experiments and numerical simulations, and initial twist in the structure is shown to have little effect on the overall behavior due to the small torsi

C'est un mythe bien vivant qu'interroge ici Christophe Leclerc, la postérité de T.E. Lawrence et ses cycles, alternant gloire et réprobation, idéalisme lumineux et mystères. Sur les deux rives de la Manche, Anglais et Français ont projeté sur ce personnage quantité de rêves et de fantasmes. Porté au pinacle ou cloué au pilori, érigé en bâtisseur de nations ou en super-espion machiavélique, dépeint en masochiste homosexuel ou en ascète préoccupé de rédemption, T.E. Lawrence a très tôt suscité la controverse. À partir d'une impressionnante bibliographie, cette synthèse restitue la variété des discours sur T.E. Lawrence, dans une admirable polyphonie.

Characterizing the interface bond of thin-ply composites is important for assessing the overall structural integrity. Due to the flexibility of thin composite laminates, it is not feasible to carry out mode I double cantilever beam (DCB) and mode II end notch flexure (ENF) tests, due to the large geometric changes undergone during testing. To reduce the compliance during testing, thick aluminum substrates are bonded to the two free-surfaces of the test laminates. DCB and ENF tests are specifically carried out in this configuration. A specific glass fiber plain weave interface of a 7-ply composite structure is tested. µCT imaging shows the presence of periodic voids of size scales of 200 µm, and local delaminated regions of 0 . 7 − 5 . 6 mm. The former is attributed to capillary effects from the glass tows, while the latter is due to insufficient resin flow during the two-cure manufacturing process.

Juin 1916. Les tribus bédouines du Hedjaz se soulèvent contre l'occupant turc. Cet ouvrage relate l'épopée d'officiers et soldats français qui luttèrent aux côtés des Arabes insurgés et du célèbre colonel britannique T.E. Lawrence. Au-delà des faits d'armes, l'auteur fait ici le récit de la confrontation politique entre la France et la Grande-Bretagne pour le contrôle du Proche-Orient. Il accorde une attention particulière au duel sans merci que se livrèrent le lieutenant-colonel Brémond, chef de la mission française, et T.E. Lawrence, pour rivaliser d'influence auprès des leaders de la révolte arabe.

High stress concentrations leading to material failure have been observed in TRAC booms coiled under tension around a circular hub. The stress concentrations are typically observed in the transition region between the fully deployed and coiled sections of the boom. A numerical simulation framework is proposed to model the coiling process analyses the stress distribution in the transition region. Isotropic booms are first studied to understand the effects of the cross-section geometry and the boundary conditions during coiling. Compressive stress is reduced by 13% and 26% by using a variable curvature cross-section and adding nip rollers in the coiling mechanism respectively. For an ultra-thin glass fiber-carbon fiber composite laminate, the compressive stress is similarly reduced by 24% and 11%. The variable curvature cross-section is shown to eliminate the stress concentration in the transition region.

We demonstrate the development of a lightweight 1.7 m X 1.7 m prototype spacecraft structure with areal density of 150 g/m^2. The structure is composed of individual ladder-type components that can be used to support flexible multi0-functional elements such as integrated power collection and wireless transmission tiles used for space solar power. This spacecraft structure design is scalable up to 60 m X 60 m. The structural design, ultra-light component manufacture and, prototype assembly are demonstrated. Shape accuracy within 0.5° from nominal is achieved and outlook for further mass reduction is described.

We have fabricated a functional prototype of an ultralight power converter tile; a modular building block for a space-based solar power system. The tile is ∼10×15 cm in area, and weighs ∼1.5 kg/m^2. It comprises a photovoltaic (PV) solar energy collector, a radio-frequency (RF) power converter, and an array of transmission antennas. The PV collector subassembly utilizes ∼15x, 1D parabolic trough reflective concentrators with triple-junction (3J) solar cells. It has areal mass of ∼0.8 kg/m^2, 74% optical efficiency, and a peak specific power of ∼230W/kg. We demonstrated wireless power transmission over a distance of ∼50 cm in our lab. Analysis of the sources of mass and inefficiency suggest a path towards achieving dramatically higher performance with future designs.

In fiber reinforced composite materials, the manufacturing process induces residual stresses and distortions that decrease the mechanical performance of the structure and affect its geometry, especially in thin laminates. Multi-physics simulations were performed to assess the spring-in effect in ultra-thin composite parabolic solar reflectors. For this purpose, a resin kinetic model has been developed by means of differential scanning calorimetry experiments. The kinetic relation has been implemented into the finite element software in order to correctly predict the evolution of the composite degree of cure during the manufacturing process. Specimens were produced in an autoclave and their final geometries were measured by means of a non-contact measuring system and compared with numerical predictions, showing very good agreement.

We demonstrate the development of a prototype lightweight (1.5 kg/m^3) tile structure capable of photovoltaic solar power capture, conversion to radio frequency power, and transmission through antennas. This modular tile can be repeated over an arbitrary area to forma large aperture which could be placed in orbit to collect sunlight and transmit electricity to any location. Prototype design is described and validated through finite element analysis, and high-precision ultra-light component manufacture and robust assembly are described.

The paper studies the behavior of Triangular Rollable and Collapsible (TRAC) booms made from ultra-thin carbon fiber, with a total flange thickness of 71 µm. Both bending and torsional behavior of the deployed booms are studied using numerical analysis and experimental testing. The coiling of the booms around hubs of large radius is also studied.