A time-domain method to solve transient elastic wave propagation in a multilayer medium with a hybrid spectral-finite element space approximation

• Published in: Wave motion 2008, Vol.45 (4), p.383-399
• Main Authors: Desceliers, C., Soize, C., Grimal, Q., Haiat, G., Naili, S.
• Format: Article
• Language: English
• Subjects: Acoustics; Biomechanics; Elastic and acoustic waves; Engineering Sciences; Exact sciences and technology; Finite element; Fundamental areas of phenomenology (including applications); Low numerical cost; Mathematical methods in physics; Mechanics; Multilayers; Numerical approximation and analysis; Ordinary and partial differential equations, boundary value problems; Physics; Solid mechanics; Structural and continuum mechanics; Time-domain; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Vibrations
• ISSN: 0165-2125; 1878-433X
• DOI: 10.1016/j.wavemoti.2007.09.001

This paper introduces a new numerical hybrid method to simulate transient wave propagation in a multilayer semi-infinite medium, which can be fluid or solid, subjected to given transient loads. The medium is constituted of a finite number of unbounded layers with finite thicknesses. The method has a low numerical cost and is relatively straightforward to implement, as opposed to most available numerical techniques devoted to similar problems. The proposed method is based on a time-domain formulation associated with a 2D-space Fourier transform for the variables associated with the two infinite dimensions and uses a finite element approximation in the direction perpendicular to the layers. An illustration of the method is given for an elasto-acoustic wave propagation problem: a three-layer medium constituted of an elastic layer sandwiched between two acoustic fluid layers and excited by an acoustic line source located in one fluid layer.