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LMS
Beijing, China

Vansant K.,LMS | Beriot H.,LMS | Bertolini C.,AUTONEUM | Miccoli G.,IMAMOTER
SAE International Journal of Engines | Year: 2014

As the legislation for pass-by noise (PBN) has recently become more stringent, car manufacturers face again a challenging task to reach the new SPL objective (70dB(A)). A good design of the engine bay is therefore required to sufficiently attenuate the noise coming from sources as the engine and the intake. This involves proper design of the engine bay's panels including apertures, and a good selection of the type and location of acoustic treatments. For a given engine bay design, the PBN SPL results can be obtained with a PBN test or by an equivalent simulation. Using simulation models it is possible to create the perfect test environment virtually and moreover to obtain acoustic results for a large number of designs upfront of any actual testing or prototype. The challenge for simulation models is however that, as the results should typically be available from 20 Hz up to 4 or 5 kHz and overall SPL results should be retrieved from a narrow band response over this large frequency range, the CAE models required can become very large and many frequencies need to be computed resulting in long solving times. This paper will discuss on Boundary Element Method (BEM) and Finite Element Method (FEM) acoustic technologies available to predict powertrain exterior Acoustic Transfer Functions (ATFs) for a mock-up model of an engine bay. A comparison with Test results is provided to judge on the models' accuracy. Special focus is given to a comparative performance study for the different simulation approaches. Copyright © 2014 SAE International. Source


Sfyris D.,FORTH ICE HT | Sfyris G.I.,LMS | Galiotis C.,FORTH ICE HT
International Journal of Solids and Structures | Year: 2015

Abstract We lay down a nonlinear elastic constitutive framework for the modeling of some 2D crystals of current interest. The 2D crystals we treat are graphene, hexagonal boron nitride and some metal dichalcogenides: molybdenium disulfide (MoS2), tungsten selenium (WSe2), and niobium diselenide (NbSe2). We first find their arithmetic symmetries by using the theory of monoatomic and diatomic 2-nets. Then, by confinement to weak transformation neighborhoods and by applying the Cauchy-Born rule we are able to use the symmetries continuum mechanics utilizes: geometric symmetries. We give the complete and irreducible representation for energies depending on an in-plane measure, the curvature tensor and the shift vector. This is done for the symmetry hierarchies that describe how symmetry changes at the continuum level: C→C→C1 for monoatomic 2-nets, and C→C→C1 for diatomic two nets. We stress that we do not take into account how energy behaves at the transition regime. Having these energies at hand we are able to evaluate stresses and couple stresses for each symmetry regime. These quantities participate to the field equations: the momentum equation, the moment of momentum equation and the equation ruling the shift vector. By making specific assumption for the loading histories that correspond to in-plane biaxial tension/compression as well as in-plane simple shear, we obtain necessary expressions for the shift vector components in order all field equations to be satisfied. When the algebraic equations ruling the shift vector render infinite solutions, we use the Cauchy-Kowalevski theorem-when it applies-for the momentum equation viewed as a quasilinear system in order to single out the unique solution. © 2015 Elsevier Ltd. Source


Escande C.,French National Center for Scientific Research | Escande C.,FESTO | Chettibi T.,LMS | Merzouki R.,French National Center for Scientific Research | And 2 more authors.
IEEE/ASME Transactions on Mechatronics | Year: 2014

This paper deals with the forward kinematic calibration of a bionic arm inspired from the organic elephant trunk and called compact bionic handling assistant (CBHA). First, a forward kinematic model is developed based on the principle of the constant curvature continuum robot theory. Then, two experimental setups are proposed in order to carry out the model calibration and validation. The first one is based on the trilateration method, while the second one is based on the coupling of the CBHA with a rigid six-degree-of-freedom rigid manipulator. The aim of the calibration is to enhance the precision of the forward kinematic model. © 2014 IEEE. Source


El Hami A.,National Institute for Applied Sciences, Strasbourg | Radi B.,LMS | Cherouat A.,University of Technology of Troyes
Simulation | Year: 2012

In this paper, we are interested particularly in the tube hydroforming process (THP). This process consists of applying an inner pressure combined with an axial displacement to manufacture the part. During the manufacturing phase, inappropriate choice of the load paths can lead to failure. Deterministic approaches are unable to optimize the process by taking into account the uncertainty. So we introduce the reliability-based design optimization (RBDO) to optimize the process under probabilistic constraints to ensure a high reliability level and stability during the manufacturing phase and avoid the occurrence of such plastic instability. Taking some uncertainties into account the process is very stable and associated with a low failure probability. The definition of the objective function and the probabilistic constraints take advantage of the forming limit diagram (FLD) and the forming limit stress diagram (FLSD) used as a failure criterion to detect the occurrence of wrinkling, severe thinning and necking. To validate the proposed approach, the THP is then introduced as an example. The numerical results show the robustness and efficiency of the RBDO to improve thickness distribution and minimize the risk of potential failure modes. © 2012 The Society for Modeling and Simulation International. Source


Trademark
Lms | Date: 2011-08-16

Pharmaceutical and dietetic preparations for well-being and beauty, namely, pharmaceutical preparations for memory, sound sleep, digestion, weight control, skincare, mineral stimulation, and bone health; pharmaceuticals and dietetic preparations for well-being and beauty, namely, preparations for use in the treatment of age-related conditions and for slowing the aging process, namely, hypertension, diabetes, arthritis, memory loss, disorders of the nervous system, age-related macular degeneration, disorders of the digestive system, osteoporosis, skin dryness and sleep disorders, antioxidant products in the form of dietary supplements containing antioxidants and medicated skincare products containing antioxidants, and cognitive products in the form of preparations to improve memory and mental acuity; pharmaceutical and dietetic preparations for well-being and beauty, namely, medicated skin care lotions, gels, creams and solutions for dermatological use, medicated serums for treatment of hair, skin and lips; vitamins and mineral supplements; Veterinary preparations for dogs and cats for well-being and beauty, namely, medicated preparations for animal skincare, mineral stimulation, and bone health; veterinary preparations for dogs and cats for well-being and beauty, namely, medicated skin care lotions, vitamins, mineral supplements, antioxidants; Nutritional supplements for medical use and pharmaceuticals in all galenic formulations for well-being and beauty, namely, pharmaceutical preparations for memory, sound sleep, digestion, weight control, skin care, mineral stimulation, and bone health; nutritional supplements for medical use and pharmaceuticals in all galenic formulations, namely, preparations for use in the treatment of age-related conditions and for slowing the aging process, namely, hypertension, diabetes, arthritis, memory loss, disorders of the nervous system, age-related macular degeneration, disorders of the digestive system, osteoporosis, skin dryness and sleep disorders, antioxidant products in the form of dietary supplements containing antioxidants and medicated skincare products containing antioxidants, and cognitive products in the form of preparations to improve memory and mental acuity; nutritional supplements for medical use and pharmaceuticals in all galenic formulations,namely, medicated skin care lotions, gels, creams and solutions for dermatological use, medicated serums for treatment of hair, skin and lips, vitamins and mineral supplements. Provision of access to electronic sites featuring blogs; blogs, namely, providing an on-line forum in the fields of health, well-being, beauty, and economic, social and environmental issues; Sites, namely, provision of access to electronic sites in the fields of health, well-being, beauty, and economic, social and environmental issues; Audiovisual communication, namely, streaming of audiovisual material on the internet; Television broadcasting. Consultancy in the field of energy-saving, namely, technological consulting services in the field of conserving energy, energy efficiency, and alternative energy generation; consultancy in the nature of technical information and advice in the field of global warming prevention, technical consultancy in the field of environmental science as it relates to the protection of biodiversity, consultancy in the field of building consultancy, namely, architectural consultancy and research on building construction or city planning; Maintenance of websites for third parties; Technical project studies in the field of computer science, namely, computer systems analysis, design and development of computer software, research and design of computer software, computer project management, conducting of feasibility studies, scientific study and research in the field of computer science; Research in biology and chemistry in the fields of beauty care and health; research in cosmetology; Research in the fields of environmental protection and sustainable development relative to protecting the environment and environmental concerns; Research and development in the field of food and food supplements.

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