Publications

2000

• Surface deformation analysis of composites by mesomechanics
  
  • Soppa E.
  • Doumalin Pascal
  • Bornert Michel
  • Schmauder S.
  , 2000, 3, pp.443-449. No abstract provided
• Influence of the film thickness on texture, residual stresses and cracking behaviour of PVD tungsten coatings deposited on a ductile substrate
  
  • Ganne T.
  • Farges G.
  • Crépin Jérôme
  • Pradeilles-Duval R. M.
  • Zaoui A.
  , 2000. No abstract provided
• Effet de la fréquence de sollicitation et de l'environnement sur la propagation des fissures de fatigue en mode II dans l'acier maraging M250
  
  • Doquet V.
  , 2000. No abstract provided
• Adaptive mesh for inelastic analysis of structures
  
  • Zarka J.
  • Hablot J. M.
  , 2000. No abstract provided
• A Concept for Earthquake-Resistant Design of Underground Structures: Stress Response Spectrum
  
  • Kurose Ayumi
  • Bérest Pierre
  , 2000, pp.1043-1049. This paper introduces a method to evaluate the mechanical effects induced in the cross-section of an underground structure, constructed in a medium of great thickness, under earthquake ground motion. Damage observations after large earthquakes (e.g., Kobe, 1995) have shown the cross-sectional vulnerability of underground structures at shallow or great depth. Present earthquake-resistant design standards only suggest calculation methods for structures constructed in a soil laying over a rigid basement and cannot be applied to a structure constructed in a medium of great thickness, such as a tunnel, an underground hydrocarbon storage facility or a nuclear-waste disposal site. Thus, development of a systematic method to evaluate the seismic effects induced in the cross-section of a structure in an unbounded medium is of interest. The approach proposed here is conceptually similar to that used for earthquake response analysis of buildings: using a simple but realistic model of an underground linear structure (a 2D cavity with circular cross-section in an infinite, elastic, linear, homogeneous and isotropic medium) and real earthquake records, we propose a response spectrum more suitable, than the usual velocity or acceleration response spectrum, for analyzing the structural stability of underground construction during earthquakes: the Stress Response Spectrum (SRS), which is defined as the maximum value of the maximum shear stress at the cavity wall during the duration of ground motion. The SRS values are computed by using 21 earthquake motions (provided by the Japan Meteorological Agency) of magnitude higher than 4, which were recorded by the Japan Nuclear Cycle Research Institute (JNC) in a 315-meter deep gallery excavated in an a granodioritic rock mass at the Kamaishi Mine in Iwate, Japan. In light of the numerical analysis, the SRS appears to be a potential tool for the earthquake-response analysis of underground structures. The Stress Response Spectrum will provide engineers with the order of magnitude of mechanical effects in an underground structure for a given earthquake motion; conversely, for a given target SRS, may assist in producing a design earthquake more suitable for analysis of deep underground structures than those currently available.
• Study of the mechanical behaviour of plasma deposited silica films on polycarbonates and steel
  
  • Hofrichter Alfred
  • Constantinescu Andrei
  • Benayoun Stéphane
  • Bulkin Pavel
  • Drévillon Bernard
  Journal of Vacuum Science & Technology A, American Vacuum Society, 2000, 18, pp.2012-2014. In the present study, we deposited amorphous hydrogenated silicon oxide films on polycarbonate, stainless steel, and silicon by plasma enhanced chemical vapor deposition using a low pressure, high density integrated distributed electron cyclotron resonance plasma reactor. Substrate curvature, vibrating slab, and Vickers indentation experiments were used to evaluate the intrinsic stress, the Young modulus of the films, and the composite hardness of the film–substrate system. The indentation experiments were modeled by finite element analysis and the calculated values were compared to experimentally measured hardness values. A reasonable accordance with the experiment was found both for stainless-steel and polycarbonate substrates, indicating that the modeling is valid and may be used to enhance the interpretation of the indentation experiments. The calculations show an important bending of the film in the noncontact region in the case of a Vickers indentation on a coated polycarbonate sample. The analysis of the thus-induced strain distribution in the coating indicates that the measured diagonal might be overestimated and not representative of the real contact area. The calculations indicate that the yield limit of the plasma-deposited silica films is of about 4 GPa. (10.1116/1.582464)
  DOI : 10.1116/1.582464
• Second-order and affine estimates for the behaviour of viscous polycrystals
  
  • Bornert Michel
  • Masson Renaud
  • Ponte-Castañeda P.
  Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik, Wiley-VCH Verlag, 2000, 80, pp.S17-S20. The recently proposed second‐order and affine estimates for the effective behavior of nonlinear heterogeneous materials rely on the same linearization procedure and refer to some “thermoelastic comparison composite”. But both approaches differ in the way the overall nonlinear answer is defined, either through average stress‐strain relations or energy considerations. When combined with the linear self‐consistent model, they provide new tools for the predictions of the behavior of viscoplastic polycrystals (steady state creep). They are compared to each other and to other more classical estimates (incremental and tangent) in the following situations.: a 2D antiplane model problem for which efficient rigorous upper bounds are available, the creep of isotropic aggregates of FCC crystals and HCP crystals with different critical stresses on the basal and prismatic slip systems. (10.1002/zamm.20000801305)
  DOI : 10.1002/zamm.20000801305