CNRS Quartz Laboratory
CNRS Quartz Laboratory
Troudi A.,CNRS Quartz Laboratory |
Addouche S.-A.,CNRS Quartz Laboratory |
Dellagi S.,CNRS Production Engineering and Mechanical Production Laboratory |
El Mhamedi A.,CNRS Quartz Laboratory
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017
This paper treats a drone delivery parcel’s problem in an urban area. Drone delivery has emerged as a potential way in the immediate future to deliver parcels in the urban area, especially in last-mile delivery. This new configuration of parcel delivery highlights the improvement of the application of Unmanned Aircraft Vehicles in the civil use. The future challenge underlying this application is not so much the design of drones for parcel delivery, but the logistics support of a massive fleet of drones with a mission to deliver at least hundreds of parcels a day in a dense urban area. We hereby treat this issue by focusing on Logistics Support System. In this paper, we propose a Post-Production Logistics Support Analysis to cover the exploitation phase of a drone delivery operator. © Springer International Publishing AG 2017.
Selles N.,MINES ParisTech |
Cloetens P.,European Synchrotron Radiation Facility |
Proudhon H.,MINES ParisTech |
Morgeneyer T.F.,MINES ParisTech |
And 4 more authors.
Macromolecules | Year: 2017
Micromechanisms of deformation and cavitation within the spherulitic microstructure of a polyamide 6 (PA6) material have been observed with a true spatial resolution of 50 nm by magnified synchrotron radiation holotomography. Smooth round bars in PA6 were submitted to interrupted monotonic tensile tests. Before the engineering peak stress, only pre-existing nanometric voids were identified. At the peak stress, void growth and coalescence have been observed in the neck and 2 mm apart from the neck along the revolution axis. Two kinds of cavity arrangements have also been identified, studied quantitatively, and attributed to specific regions of the deformed spherulites. Voiding appeared in the equatorial plane of the spherulites as diffuse annular voided zones, and polar fans were characteristically penny-shaped voids stacked in columns parallel to the loading axis in the spherulite poles. A cylindrical volume located at the center of these spherulites remained intact (no voids). © 2017 American Chemical Society.
Etienne L.,CNRS Quartz Laboratory |
Di gennaro S.,University of L'Aquila |
Barbot J.-P.,CNRS Quartz Laboratory
International Journal of Robust and Nonlinear Control | Year: 2017
In this paper, we investigate the observation and stabilization problems for a class of nonlinear Lipschitz systems, subject to network constraints, and partial state knowledge. In order to address these problems, an impulsive observer is designed, making use of the event-triggered technique in order to diminish the network communications. Sufficient conditions are given to ensure a milder version of the separation principle for these systems, controlled via an event-triggered controller. The proposed observer ensures practical state estimation, while the corresponding dynamic controller ensures practical stabilization. The sampling and the data transmission are carried out asynchronously. The dynamic controller is tested in simulation on a flexible joint. © 2017 John Wiley & Sons, Ltd.
Griffiths S.,CNRS Quartz Laboratory |
Nennig B.,CNRS Quartz Laboratory |
Job S.,CNRS Quartz Laboratory
Journal of the Acoustical Society of America | Year: 2017
A theoretical and experimental study of the acoustic absorption of granular porous media made of non-cohesive piles of spherical shells is presented. These shells are either rigid or elastic, possibly drilled with a neck (Helmholtz resonators), and either porous or impervious. A description is given of acoustic propagation through these media using the effective medium models proposed by Johnson (rigid particles) and Boutin (rigid Helmholtz resonators), which are extended to the configurations studied in this work. A solution is given for the local equation of elasticity of a shell coupled to the viscous flow of air through the neck and the micropores. The models and the simulations are compared to absorption spectra measured in reflection in an impedance tube. The effective medium models and the measurements show excellent agreement for configurations made of rigid particles and rigid Helmholtz resonators that induce an additional peak of absorption at low frequency. A shift of the Helmholtz resonance toward low frequencies, due to the softness of the shells is revealed by the experiments for elastic shells made of soft elastomer and is well reproduced by the simulations. It is shown that microporous shells enhance and broaden acoustic absorption compared to stiff or elastic resonators. © 2017 Acoustical Society of America.
Di Maio D.,University of Bristol |
Bozzo A.,CNRS Quartz Laboratory |
Peyret N.,CNRS Quartz Laboratory
AIP Conference Proceedings | Year: 2016
This study aims to present a novel work aimed at locating discrete nonlinearities in mechanical assemblies. The long term objective is to develop a new metric for detecting and locating nonlinearities using Scanning LDV systems (SLDV). This new metric will help to improve the modal updating, or validation, of mechanical assemblies presenting discrete and sparse nonlinearities. It is well established that SLDV systems can scan vibrating structures with high density of measurement points and produc e highly defined Operational Deflection Shapes (ODSs). This paper will present some insights on how to use response phase mapping for locating nonlinearities of a bolted flange. This type of structure presents two types of nonlinearities, which are geometr ical and frictional joints. The interest is focussed on the frictional joints and, therefore, the ability to locate which joint s are responsible for nonlinearity is seen highly valuable for the model validation activities. © 2016 Author(s).
Wolf J.,CNRS Clement Ader Institute |
Longere P.,CNRS Clement Ader Institute |
Cadou J.M.,French National Center for Scientific Research |
Crete J.P.,CNRS Quartz Laboratory
International Journal of Mechanics and Materials in Design | Year: 2017
The present work aims at numerically predicting the current residual strength of large engineering structures made of ductile metals against accidental failure. With this aim in view, the challenge consists in reproducing within a unified finite element-based methodology the successive steps of micro-voiding-induced damage, strain localization and crack propagation, if any. A key ingredient for a predictive ductile fracture model is the proper numerical treatment of the critical transition phase of damage-induced strain localization inside a narrow band. For this purpose, the strong discontinuity cohesive model and the eXtended Finite Element Method are combined. A propagation algorithm is proposed and studied in the context of ductile materials. Physics-motivated criteria to pass from the phase of more or less diffuse damage to strain localization and from strain localization to crack propoagation are proposed. Finally, a 2D numerical example is shown to study the performance of the failure analysis model when implemented into an engineering finite element computation code, namely Abaqus. © 2017 Springer Science+Business Media Dordrecht
Ghanes M.,CNRS Research Institute of Communication and Cybernetics of Nantes |
DeLeon J.,Autonomous University of Nuevo León |
Barbot J.-P.,CNRS Quartz Laboratory |
Barbot J.-P.,French Institute for Research in Computer Science and Automation
Journal of the Franklin Institute | Year: 2016
In this paper, a class of time-delayed nonlinear systems with unknown parameters and unknown time-varying delays is considered. A high gain observer approach is proposed for simultaneous state observation and parameter identification. Sufficient conditions are obtained to ensure the boundedness of both observation and identification errors. Consequently a practical stability of the proposed observer is achieved. Moreover, an exponential stability of the observer is derived from the knowledge of time-delay. Simulation results are given to illustrate the performances of the proposed observer design under time-varying delay function and a piecewise unknown parameter. © 2016 The Franklin Institute.
Binois R.,CNRS Roberval Laboratory (Mechanical Research Unit) |
Binois R.,CNRS Quartz Laboratory |
Perrey-Debain E.,CNRS Roberval Laboratory (Mechanical Research Unit) |
Dauchez N.,CNRS Roberval Laboratory (Mechanical Research Unit) |
And 3 more authors.
Acta Acustica united with Acustica | Year: 2015
To estimate the efficiency of parallel baffle-type silencers in rectangular ducts, a two-dimensional multi-layer model is presented for predicting their transmission loss. The approach takes into account an arbitrary number of bulk reacting baffles of finite length bounded at both ends by a metallic fairing. Each layer is described by a mean pressure, which allows computing a piecewise constant modal basis for the mean pressure over the cross section. The continuity between the incoming and outgoing waves is performed by axial mode matching at the inlet and outlet cross-sections of the baffle silencer. It is shown that the model is easy to implement and suitable for optimization purposes based on design parameters such as the height of each baffle, their relative positions in the duct, and material properties. Relatively complex configurations can be simulated with relatively modest computational effort. An experimental campaign was carried out on a reduced scale test bench for standard configurations. The numerical results are in good agreement with the measurements. Noise reduction performances are analyzed in terms of reflected and dissipated sound powers. Finally, more complex geometric configurations are simulated in order to examine the influence of the relative transverse and axial positions of each baffle as well as the effect of a resistive screen between the baffles and the airways. © S. Hirzel Verlag • EAA.
Fortes Da Cruz J.,CNRS Quartz Laboratory |
Da Silva Botelho T.,CNRS Quartz Laboratory |
Lemaire-Caron I.,CNRS Quartz Laboratory |
Durand A.-M.,ACM |
Messager D.,JPB Systeme
Tribology International | Year: 2016
Inconel 718 flat rough surfaces were tested under fretting conditions at room and high temperature (600°C). Analysis were focused on friction coefficient, damage and fretting regime. Several coatings were tested, and showed significant differences depending on the test temperature. The bonded coating offers good protection against fretting wear at ambient temperature but loses its properties at 600°C where the CrC shows excellent durability and lower friction thanks to the formation of a few micrometers thin glaze layer. WS2 solid lubricant layers also show a similar protective behaviour at high temperature but under lighter normal loads and for a lower lifespan. © 2016.
Casimir J.B.,CNRS Quartz Laboratory |
Khadimallah M.A.,University of Carthage |
Khadimallah M.A.,Prince Sattam Bin Abdulaziz University |
Nguyen M.C.,Hanoi University of Science and Technology
Computers and Structures | Year: 2016
This paper describes a procedure for taking into account distributed loads in the calculation of the harmonic response of a cross-ply laminated circular cylindrical shell using the dynamic stiffness method. This work is a direct continuation of a previous work concerning isotropic materials. Equivalent loads are established on element boundaries to determine the response of the system. Therefore, the vibration analysis is solved with numerical examples in order to determine the performances of this approach. The method allows reducing both the size of the model and computing time, and ensures higher precision compared to the finite element method. © 2016 Elsevier Ltd. All rights reserved.