title: Two-dimensional wave propagation in an elastic half-space with quadratic nonlinearity: a numerical study.
abstract: This study investigates two-dimensional wave propagation in an elastic half-space with quadratic nonlinearity. The problem is formulated as a hyperbolic system of conservation laws, which is solved numerically using a semi-discrete central scheme. These numerical results are then analyzed in the frequency domain to interpret the nonlinear effects, specifically the excitation of higher-order harmonics. To quantify and compare the nonlinearity of different materials, a new parameter is introduced, which is similar to the acoustic nonlinearity parameter beta for one-dimensional longitudinal waves. By using this new parameter, it is found that the nonlinear effects of a material depend on the point of observation in the half-space, both the angle and the distance to the excitation source. Furthermore it is illustrated that the third-order elastic constants have a linear effect on the acoustic nonlinearity of a material.
authors.affiliation: Institute for System Dynamics, University of Stuttgart, Stuttgart, Germany. sebastian.kuechler@isys.uni-stuttgart.de
authors.forename: Sebastian
authors.initials: S
authors.lastname: Küchler
authors.forename: Thomas
authors.initials: T
authors.lastname: Meurer
authors.forename: Laurence J
authors.initials: LJ
authors.lastname: Jacobs
authors.forename: Jianmin
authors.initials: J
authors.lastname: Qu