In this paper, the mechanical properties of plasma-sprayed coatings are evaluated usingthe technology of nanoindentation. According to the indentation curve (load versusindenter’s displacement), which is recorded in an indentation experiment, the mechanicalbehaviour of the plasma-sprayed coating is investigated via inverse analysis usingnumerical optimization algorithms. The tip rounding of imperfect indenter is investigatedin parameter identification. Subsequently, the hardness on the top surface and on thevertical cross section of the plasma-sprayed coating are investigated. The results showthat the hardness on the top surface of the coating depends on the indentation depth.Moreover, the results show that the hardness on the cross section of the coating issignificantly affected by the substrate if the indentation impression is too close to thecoating-substrate interface.

In the present study, an enriched continuum mechanics framework is employed to study thesurface effects on bending behavior of silver nanowires (NWs) resting on elasticsubstrate. The Timoshenko beam theory and the Laplace-Young equation are employed toinvestigate static behavior of silver NWs lying on Winkler-Pasternak elastic substrate.Three types of boundary conditions are considered as doubly simply supported (S-S), doublyclamped (C-C) and cantilevered (C-F). Analytical solutions are obtained for NWs withsurface crystallographic orientation of [001] subjected to a concentrated external force.By defining different normalized contact stiffness, extensive numerical results arecarried out to study the influence of effective parameters such as substrate, surface,aspect ratio (L/D) and diameter onthe stiffness of NWs. According to the obtained results, the effect of surface and itsrate of variation on stiffness of NWs lying on Winkler and Winkler-Pasternak elasticfoundation models are more significant in (C-F) type of boundary condition compared to theNWs without foundation. By increasing the modulus of elastic substrate, the effect ofshear deformation increases which it is more considerable in (C-C) and (S-S) NWs restingon the Winkler-Pasternak and Winkler substrate models, respectively.

This paper presents experimental and numerical studies of drop tests of corrugatedcardboard packaging containing different foam cushions. An efficient homogenization modelfor the corrugated cardboard has been developed. In our homogenized model, the corrugatedcardboard is represented by a 2D plate. Instead of using a local constitutive law(relating the strains to the stresses) at each material point, the homogenization givesthe global rigidities (relating the generalized strains to the resultant forces) for theequivalent homogeneous plate. This model was implemented into the FE software ABAQUS. Thefoam behaviour was experimentally determined and modelled using a crushable foam model ofABAQUS. The packages are tested in free fall from a given height on a rigid floor. Thedeceleration of the packed product was recorded using a triaxial accelerometer. Thenumerical results obtained using the FE simulation with the homogenized model agree wellwith the experimental results. We have also shown that the contribution of the corrugatedcardboard box to the shock response could not be neglected in the design of cushioningpackage.

The study of nonlinear dynamic behavior of laminate composed of steel and rubber layersalso referred as “Shim”, used for vibro-acoustic insulation in brake system, isinvestigated. The simulation of the vibro-acoustic nonlinear behavior of Shim depending onfrequency, taking into account the large deformations and various nonlinearhyper-viscoelastic laws of rubber are considered. This paper presents a solution tocontribute in the identification of the best design of Shim in terms of damping vibrationof brake systems, using analytical and numerical method. The choice of the best structuredepends essentially on the nature of rubber, on the stacking sequence of materials, ontheir thickness, on the number of layers and on volume fraction of rubber. An analyticalstudy, with the use of the transfer matrix method is presented. A model on the finiteelement software ANSYS is constructed. The results lead to conclusions about the beststructure and design of Shim in term of vibro-acoustic insulation.

In this paper, the cyclostationary characteristics of electrical signals will beexploited in order to detect the rotor faults of an asynchronous machine. These defectsare the most complex in terms of detection since they interact with the 50 Hz carrier witha weak band occupied in frequency. The testing ground used includes an industrialthree-phase wound rotor asynchronous motor of 400 V, 6.2 A, 50 Hz, 3 kW, 1385 rpmcharacteristics. The rotor fault has been carried out by adding an extra 40 mΩ resistanceon one of the rotor phases (i.e. 10% of the rotor resistance value per phase,Rr = 0.4Ω). From the stator voltage andcurrent acquisition, and by application of the Time Synchronous Averaging (TSA) method tothe stator current, the electrical signal will be conditioned in order to obtain asensitive indicator allowing to easily distinguish the healthy cases from defective ones.

Dimensional errors of the parts from a part family cause the initial misplacement of theworkpiece on the fixture affecting the final product quality. Even if the part ispositioned correctly, the external machining forces and clamping load cause the part todeviate from its position. This deviation depends on the external load and the fixturestiffness. In this article, a comprehensive analytical model of a 3-2-1 fixturing systemis proposed, consisting of a kinematic and a mechanical part. The kinematic modelrelocates the initially misplaced workpiece in the machine reference through the axialadvancements of six locators taking all the fixturing elements to be rigid. Therepositioned part then shifts again from the corrected position due to the deformation offixturing elements under clamping and machining forces. The mechanical model calculatesthis displacement of the part considering the locators and clamps to be elastic. The rigidcuboid baseplate, used to precisely relocate the workpiece, is also considered elastic atthe interface with the locators. Using small displacement hypothesis with zero friction atthe contact points, Lagrangian formulation enables us to calculate the rigid bodydisplacement of the workpiece, deformation of each locator, as well as the stiffnessmatrix and mechanical behavior of the fixturing system. This displacement of the workpieceis then finally compensated by the advancement of the six axial locators calculatedthrough the kinematic model.

Probability Density Function (PDF) is often selected to couple chemistry with turbulencefor complex reactive flows since complex reactions can be treated without modelingassumptions. This paper describes an investigation into the use of the particlesapproximation of this transport equation approach applied to Homogeneous ChargeCompression Ignition (HCCI) combustion. The model used here is an IEM (Interaction byExchange with the Mean) model to describe the micromixing. Therefore, the fluid within thecombustion chamber is represented by a number of computational particles. Each particleevolves function of the rate of change due to the chemical reaction term and the mixingterm. The chemical reaction term is calculated using a reduced mechanism of n-heptaneoxidation with 25 species and 25 reactions developed previously. The parametric study witha variation of the number of particles from 50 up to 104 has been investigatedfor three initial distributions. The numerical experiments have shown that the hatdistribution is not appropriate and the normal and lognormal distributions give the sametrends. As expected when the number of particles increases for homogenous mixture (i.e.high turbulence intensity), the in-cylinder pressure evolution tends towards thehomogeneous curve. For both homogeneous and inhomogeneous (i.e. low turbulence intensity)cases, we have found that 200 particles are sufficient to model correctly the system, witha CPU time of a few minutes when a restriction of initial distribution is adopted.