A Simple Numerical Absorbing Layer Method in Elastodynamics

Jean-François Semblat (1) , Ali Gandomzadeh (1) , Luca Lenti (1)

1 LCPC/MSRGI - Division Mécanique des Sols des Roches et de la Géologie de l'Ingénieur

The numerical analysis of elastic wave propagation in unbounded media may be difficult to handle due to spurious waves reflected at the model artificial boundaries. Several sophisticated techniques such as nonreflecting boundary conditions, infinite elements or absorbing layers (e.g. Perfectly Matched Layers) lead to an important reduction of such spurious reflections. In this Note, a simple and efficient absorbing layer method is proposed in the framework of the Finite Element Method. This method considers Rayleigh/Caughey damping in the absorbing layer and its principle is presented first. The efficiency of the method is then shown through 1D Finite Element simulations considering homogeneous and heterogeneous damping in the absorbing layer. 2D models are considered afterwards to assess the efficiency of the absorbing layer method for various wave types (surface waves, body waves) and incidences (normal to grazing). The method is shown to be efficient for different types of elastic waves and may thus be used for various elastodynamic problems in unbounded domains.

Mots clés: elastic wave; absorbing boundaries; finite element method; absorbing layers; artificial boundaries; Rayleigh damping

Domaines: Mécanique des structures [physics.class-ph]; Mécanique des structures [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]

Jean-François Semblat, Ali Gandomzadeh, Luca Lenti. A Simple Numerical Absorbing Layer Method in Elastodynamics. Comptes Rendus Mécanique, 2010, 338 (1), pp.24-32. ⟨10.1016/j.crme.2009.12.004⟩. ⟨hal-00512857⟩