Modelling of the Shear Horizontal Waves High-Order Harmonics Generation Using Local Interaction Simulation Approach

Abstract

In the last few years, researchers have paid more and more attention to Shear Horizontal (SH) waves propagation characteristics as new approach used for damage detection. In particular, the fundamental SH0 mode is interesting due to its non-dispersive characteristics and single-mode existence in a certain range of frequency. These features offer promising applicability for developing a new Structural Health Monitoring technique. In order to examine damage detection features of the SH0, it is necessary to first investigate it via numerical simulations. Thus, in this paper, a new modelling approach is developed, based on the Local Interaction Simulation Approach (LISA), which allows to selectively simulate the propagation of SH waves. Both linear and nonlinear material definitions are taken into consideration to investigate propagation features of the aforementioned waves. In the latter case, the Landau-Lifshitz model and the Green-Lagrange strain-displacement relation is used. Furthermore, a local type of nonlinearity, such as a crack, is introduced to the model as well. The high-order harmonics generation is investigated for various cases, depending on the particular presence of the nonlinearity source. Based on the simulation results, the influence of propagation distance on the magnitude of high-order harmonics is evaluated and a comparative analysis is carried out in order to distinguish the sources of the nonlinearity. Presented results demonstrate that LISA is a sufficient tool for the SH-wavefield analysis.