Effect of Conical Profile on the Transmission of Elastic Waves from Cylindrical Waveguide to Bulk

This paper studies the transmission of elastic waves into test specimens for cylindrical waveguide-based ultrasonic transducers. However, to achieve better mode focusing, topographical waveguides with conical profiles were studied. Finite element simulations were used to study wave propagation and transmission into specimen samples using such "transmission horns." Fundamental longitudinal mode L(0,1) was generated in cylindrical rods. Results from both finite element simulations and experiments show that a 50-deg conical transition profile help achieve better transmission and beam directionality into the specimen and also better reception of the back wall reflections at the waveguide as compared to a simple cylindrical rod waveguide.