Laser ultrasound measurement and finite-element simulation on the dispersion behaviors of acoustic waves propagating along wedges with bilinear cross sections

In this research, dispersion behaviors of anti-symmetric flexural (ASF) modes propagating along the tip of a bilinear wedge (BW) are investigated. A BW has a cross section with two apex angles, as opposed to a linear wedge (LW) whose cross section has a single apex angle. In the literature, many studies regarding the dispersion behaviors of ASF modes have been reported for LWs, but not for BWs. In this study, laser ultrasonic measurements and finite-element numerical simulations are used to investigate the dispersion behavior of BW-ASF modes. It was found that a BW-ASF mode arises as a result of mode coupling between two LW-ASF modes of the same order corresponding to the two apex angles of the BW.