Fatigue and Damage Tolerance Assessment of 3-D Reinforced CFRP Bonded Joints

An experimental campaign has been carried out to investigate the behavior of co-bonded CFRP joints with a novel design incorporating a through the thickness local reinforcement. Different specimens were manufactured to investigate static and fatigue behavior, as well as delamination size after impact and damage tolerance characteristics. Mechanical performance of specimens with a reinforcement based on the insertion of spiked thin metal sheets between the co-bonded laminates were compared with purely co-bonded joints. This novel design demonstrated by tests a more predictable failure with respect to the standard design based solely on adhesive structural bonding. The tests allowed obtaining a significant number of experimental results that can be used to define preliminary design guidelines

Friction stir welds with enhanced fatigue strength and life post laser peening

This study aims to quantify the influence of laser peening on the structural integrity of a FSWelded aluminium fuselage joint. Fatigue tests with different stress amplitudes were performed for samples in as-machined and friction stir welded conditions to characterise the loss of fatigue strength and the effect of stress amplitude on the degradation of fatigue life. Optimisation of laser parameters was carried out to achieve an appropriate through-thickness stress profile. The optimised parameters were used to peen tensile coupon specimens and analyse the fatigue life recovery. The residual stress fields were quantified using the central incremental hole drilling method on peened and unpeened samples. It was found that both the microstructure and superposition of residual stresses from the welding process and peening treatment play a crucial role in the fatigue behaviour of the FSWelded joint. Using the parameters and layout described in this article, laser peening was able to increase the fatigue life of as-welded samples by a factor of 2.4 for the lower end of the load spectrum tested. This represents a recovery of 65% when compared to the pristine aluminium reference samples

Computer applications to digestive endoscopy

Esculape est un système de gestion de données établi à l'usage d'unités d'endoscopie digestive travaillant avec un système informatique en réseau ou avec un ordinateur personnel de type MS-DOS. Ce système permet les activités suivantes: compiler le rapport du diagnostic, des investigations et procédés opératoires des voies digestives supérieures ― inférieures ― bilio-pancréatiques y compris la laparoscopie, de stocker les données d'endoscopie et les données cliniques et de les récupérer, de produire automatiquement le rapport, de saisir et de stocker les images en cours d'examen endoscopique et de les traiter simultanément, de fournir l'analyse statistiques des données enregistrées, enfin d'enregistrer et de décoder les observations histologiques relatives aux patients. L'élaboration du rapport est simplifiée grâce à l'utilisation de fenêtres (windows), de menus à options et de la méthode automatique «POP-UP