Numerical studies of ultrasonic waves on the surface of curved objects

This work is motivated by experiments by the authors towards the inspection of ceramic ball-bearings using ultrasonic surface waves. 2D and 3D Finite Element (FE) simulation results validating the experiments and throwing light on multiple round-trips of surface waves are first presented. The change in the dispersion properties of surface waves due to curvature is then numerically demonstrated for the cases of long circular cylinder and thin circular disk, along with physical insight into how this comes about. Observations of differences in the properties of ultrasonic surface waves generated by normal and tangential excitation in both cases are then presented and discussed in light of differences in mode shapes. Finally directions for further investigation are discussed. © 2012 American Institute of Physics.