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La Garenne-Colombes, France

PSA Peugeot Citroën is a French multinational manufacturer of automobiles and motorcycles sold under the Peugeot, Citroën and DS marques. PSA is listed on the Euronext Paris stock exchange and is not a constituent of the CAC 40 index.Headquartered in the 16th arrondissement of Paris, PSA is in 2012 the second-largest Europe-based automaker, and the 9th largest in the world measured by unit production . Wikipedia.

Szmytka F.,PSA Peugeot Citroen | Maitournam M.H.,Ecole Polytechnique - Palaiseau | Remy L.,MINES ParisTech Center of materials
Computers and Structures | Year: 2013

Thermomechanical fatigue (TMF) design has nowadays become essential for many industrial parts and cyclic elasto-viscoplastic constitutive models and their numerical integration are the crucial point of the problem. The paper first presents an implicit time integration scheme for an advanced constitutive model. This scheme is based on the return-mapping algorithm and proposes a use of the viscoplastic multiplier which enables to avoid Jacobian matrixes inversion and high computational cost. This peculiar numerical model is then integrated in a comprehensive computational TMF lifetime approach. The couple is shown to give the best agreement in terms of TMF lifetime estimation when compared with more simple TMF design approaches and an other constitutive model. © 2013 Elsevier Ltd. All rights reserved.

Meliga P.,French National Center for Scientific Research | Pujals G.,PSA Peugeot Citroen | Serre T.,French National Center for Scientific Research
Physics of Fluids | Year: 2012

We use adjoint-based gradients to analyze the sensitivity of turbulent wake past a D-shaped cylinder at Re = 13000. We assess the ability of a much smaller control cylinder in altering the shedding frequency, as predicted by the eigenfrequency of the most unstable global mode to the mean flow. This allows performing beforehand identification of the sensitive regions, i.e., without computing the actually controlled states. Our results obtained in the frame of 2-D, unsteady Reynolds-averaged Navier-Stokes compare favorably with experimental data reported by Parezanović and Cadot [J. Fluid Mech.693, 115 (2012)] and suggest that the control cylinder acts primarily through a local modification of the mean flow profiles. © 2012 American Institute of Physics.

Ture Savadkoohi A.,National School of Public Civil Engineering | Lamarque C.-H.,National School of Public Civil Engineering | Dimitrijevic Z.,PSA Peugeot Citroen
Nonlinear Dynamics | Year: 2012

The concept of the vibratory energy transfer between a linear master DOF and a nonsmooth nonlinear energy sink (NES) in the presence of gravity forces is studied. Different invariant manifolds of the system at different time scales are revealed and necessary conditions for leading the behavior of the system to strongly modulated response (SMR) are enlightened. © Springer Science+Business Media B.V. 2012.

Debono M.-W.,PSA Peugeot Citroen
Plant Signaling and Behavior | Year: 2013

Taking as a basis of discussion Kalanchoe's spontaneous and evoked extracellular activities recorded at the whole plant level, we put the challenging questions: do these low- voltage variations, together with endocellular events, reflect integrative properties and complex behavior in plants? Does it reflect common perceptive systems in animal and plant species? Is the ability of plants to treat short-term variations and information transfer without nervous system relevant? Is a protoneural construction of the world by lower organisms possible? More generally, the aim of this paper is to reevaluate the probably underestimated role of plant surface potentials in the plant relation life, carefully comparing the biogenesis of both animal and plant organisms in the era of plant neurobiology. Knowing that surface potentials participate at least to morphogenesis, cell to cell coupling, long distance transmission and transduction of stimuli, some hypothesis are given indicating that plants have to be studied as environmental biosensors and non linear dynamic systems able to detect transitional states between perception and response to stimuli. This study is conducted in the frame of the "plasticity paradigm," which gives a theoretical model of evolutionary processes and suggests some hypothesis about the nature of complexity, information and behavior. © 2013 Landes Bioscience.

Grandemange M.,ENSTA UME | Cadot O.,ENSTA UME | Gohlke M.,PSA Peugeot Citroen
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012

Experimental observation of a permanent reflectional symmetry breaking (RSB) is reported for a laminar three-dimensional wake. Based on flow visualizations, a first bifurcation from the trivial steady symmetric state to a steady RSB state is characterized at Re=340. The RSB state becomes unsteady after a second bifurcation at Re=410. It is found that this RSB regime is persistent at large Reynolds numbers and is responsible for a bistable turbulent wake. © 2012 American Physical Society.

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