Additive manufacturing processes, used for more than 25 years, are no longer confined torapid prototyping applications. Mostly used nowadays in niche markets (medicalapplications, aerospace...) to manufacture metallic parts, they should provideimprovements in terms of time-to-market, ecological impact and design compared totraditional industrial processes. Current metallic additive manufacturing studied in thispaper are Selective Laser Sintering, Direct Metal Laser Sintering, Selective LaserMelting, Electron Beam Melting and Direct Metal Deposition. The performances of theseprocesses are investigated through criteria derived from the time cost quality triangleand some prospects concerning these processes are given.

This paper presents a ductile damage-gradient based nonlocal and fully coupledelastoplastic constitutive equations by adding a Helmholtz equation to regularize theinitial and boundary value problem (IBVP) exhibiting some damage induced softening. First,a thermodynamically-consistent formulation of gradient-regularized plasticity fullycoupled with isotropic ductile damage and accounting for mixed non linear isotropic andkinematic hardening is presented. For the sake of simplicity, only a simplified version ofthis model based on von Mises isotropic yield function and accounting for the singlenonlinear isotropic hardening is studied and implemented numerically using an in house FEcode. An additional partial differential equation governing the evolution of the nonlocalisotropic damage is added to the equilibrium equations and the associated weak formsderived to define the IBVP (initial and boundary value problem). After the time and spacediscretization, two algebraic equations: one highly nonlinear associated with theequilibrium equation and the second purely linear associated with the damage non localityequation are obtained. Over a typical load increment, the first equation is solvediteratively thanks to the Newton-Raphson scheme and the second equation is solved directlyto compute the nonlocal damage \hbox{$\Bar{{D}}$}D̅ at each node. All the constitutive equations are “strongly” affected bythis nonlocal damage variable transferred to each integration point. Some applicationsshow the ability of the proposed approach to obtain a mesh independent solution for afixed value of the length scale parameter. Comparisons between fully local and nonlocalsolutions are given.

Vibration and wear debris analyses are the two main conditions monitoring techniques for machinery maintenance and fault diagnosis. In addition, numerical simulation can provide useful tools to assess the proper functioning of industrial machines. We use different suspension theories with a concern of the effect of solid particles liquid lubricant itself on bearing behavior. We consider both simple models based on the Einstein’s mixture theory and a micropolar fluid theory, which is characterized by the presence of suspended rigid micro-structured particles. We suppose in this study that there are no abrasion and no wear (which are not beneficial for the contact performances) due to the presence of particles. Thus in this case we found theoretically that the presence of rigid particles in the lubricant increases the effective viscosity which enhances the load-carrying capacity as well as the minimum film thickness.

The present work fosters experimental measurements and mathematical modelling techniquesto primarily determine the thermal and the relative humidity characteristics in theair-conditioned surgical operating room. The present work also demonstrates the effect ofthe various designs of surgical operating rooms and operational parameters on the flowpattern and temperatures characteristics. This study is a part of a more comprehensiveinvestigation of the more important factors affecting the air environments in surgicaloperating room. Measured and predicted temperatures and relative humidity profiles areshown to be in good agreement. The present paper introduces several recommendationsregarding the optimum design requirements of operating rooms to provide hygiene andcomfort environment. Low humidity affects comfort and health. The present work offersexamples of measured relative humidity profiles in an operating room in (New Kasr El-AiniTeaching Hospital – 1200 beds – Cairo University – Egypt). These experimental results werecarried out to verify the proposed numerical procedure and particularly in the vicinity ofthe supply outlets and operating table.

The studied movement is the “offset” skating technique. It is typically used by the skierfor higher-force-requirement situations: climbing up a hill, handling conditions (slowsnow or head-wind) or in low force situations. It is a thrust with the both poles for eachfull stroke-cycle of the legs. Firstly, we have made a model of a skier for a movementcycle and secondly a mechanical analysis to validate this model. This work was made thanksto the biomechanics software “LifeModeler”, plug-in of ADAMS software, which is akinematic and dynamic simulation tool. LifeModeler creates a human body as ananthropomorphic robot and ADAMS allows equipping it with tools and placing it on a ground.We have built a dynamic model in 3D for the skier in its environment, that is, with itsequipment on the snow. The final goal is to analyze performances parameters effect and tomaximize the movement effectiveness, what is possible by perfecting gesture, equipment andby optimizing materials used in this sport.

On étudie expérimentalement l’écoulement turbulent pariétal produit par l’impact d’un jet frappant normalement un disque coaxial en rotation. La méthode utilisée est l’anémométrie à fil chaud : on mesure les vitesses moyennes, ainsi que les contraintes turbulentes dans un domaine où les effets de l’alimentation par le jet axial et ceux de la rotation du disque sont du même ordre de grandeur. On se place dans le cadre des approximations de couche limite pour obtenir une formulation simplifiée du problème. Par ailleurs, on met en évidence les paramètres sans dimensions qui jouent un rôle significatif. L’étude expérimentale est conduite en faisant varier ces paramètres. L’analyse des résultats expérimentaux fournit les échelles caractéristiques des vitesses et des longueurs, ainsi que le niveau de turbulence. De plus, elle donne des informations sur l’importance relative des différents termes des équations de Reynolds et permet de vérifier la validité de l’approximation de couche limite.