Measurement of the Rayleigh wave polarization using 1D Laser vibrometry

The paper presents measurement procedures for the evaluation of velocity/displacement components of surface elastic waves through a single beam Laser Vibrometer. The developed technique is applied for the estimation of Rayleigh wave polarization in aluminum specimens. The estimated polarization orbits are compared with the analytical ones to demonstrate the effectiveness of the measurement technique. The estimations rely on the preliminary analysis of the recorded signals in the frequency/wavenumber domain, as enabled by the fine spatial resolution provided by a scanning Laser vibrometer, which allows identification and separation of Rayleigh waves from the recorded wavefield. In addition, comparison of polarization measurements performed on untreated and shot-peened samples suggests the measurement technique as a tool for the estimation of the effect of residual stresses on the polarization properties of surface waves.