LMA - Laboratoire de Mécanique et d’Acoustique

Theme Modeling for waves

This topic includes theoretical and methodological research performed in the "Waves and Imaging" team. The main goal is to better understand mechanical wave propagation phenomena in complex media, from the mathematical analysis of the equations involved to the development of numerical simulation codes and tools, for the characterization of the different kind of media in which acoustic waves propagate. This research is often motivated by the application areas covered by the other research topics of the team.

Main scientific goals

  • Elastodynamics: analysis of transient waves in dissipative or anisotropic media, wave/interface interaction, propagation of nonlinear waves
  • Numerical modeling: development and analysis of numerical methods
  • Scientific computing: development of optimized calculation tools and programs both in 2D and in 3D, high-performance computing
  • Imaging and inversion

Topics addressed

  • Surface waves in anisotropic media, transient waves in porous media, acoustic solitons, multi-diffusion
  • Wave/interface interaction: imperfect bonding, steep topography...
  • High-order numerical schemes, discretization of fractional derivatives, numerical integration in the case of nonlinear waves, immersed interface method, absorbing layers
  • Modified finite differences (MiDiPack), spectral finite elements (SPECFEM), high-performance computing based on GPU graphics cards or Intel MIC accelerator boards
  • Adjoint-based tomography or full-waveform inversion, iterative resolution of inverse problems

Contribution to socio-economical aspects

Development of applications and studies specific to these fields

  • Energy and Environment: underwater acoustics, seismic tomography and seismic hazard studies (numerical simulation of earthquakes)...
  • Military: numerical simulation of the acoustic response of old buried mines...
  • Non-destructive testing: concrete, steel, other materials...
  • Health: characterization of osteoporosis ...

Development of free software

Collaborations

Académic

  • international:
    • Princeton Univ., Florida Univ., Louisville Univ., Delaware Univ. (USA)
    • Barcelona Supercomputing Center (Spain)
    • Institut National de Géophysique et Vulcanologie, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (Italy)
    • Dortmund Univ. (Germany)
    • Toronto Univ. (Canada)
    • Univ. d’Alger (Algeria)
    • Univ. de Nairobi (Kenya)
  • national: LAUM (Le Mans), JADE (Nice), M2P2 (Marseille), IRMAR (Rennes), ISAE (Toulouse)

National labs and industrial partners

  • CEA, INRIA (POEMS, Paris, France)
  • EDF, TOTAL

Members

Harold Berjamin Paul CRISTINI Nathalie FAVRETTO-CRISTINI Dimitri KOMATITSCH Bruno LOMBARD Marc PACHEBAT Cédric Payan