Numerical evaluation of horn geometry influence on VHCF ultrasonic test parameters

The study presents a numerical investigation of the influence of horn geometry on the performance of a 20 kHz ultrasonic testing system used for Very High Cycle Fatigue (VHCF) applications. The system, comprising an aluminium horn and duplex 2205 steel specimen, was evaluated using COMSOL Multiphysics. Four horn geometries – conical, stepped-conical, exponential, and stepped-cylindrical – were analysed to compare their ability to amplify displacement and stress under varying input voltages. Findings indicate the importance of horn geometry in achieving optimal resonance and mechanical amplification, offering valuable insight for the design of efficient ultrasonic fatigue testing systems.