Design and Magnification Factor Analysis of Multi-linear Stepped Ultrasonic Horn for Machining Application Using FEM Approach

This work reports the design and development of ultrasonic horns used in ultrasonic machining operations. The horn design determines the performance of ultrasonic machining, which in turn is the function of its geometric aspects and material. The geometric modeling of the horn is carried out using Creo software. We consider the frequency range of 20–25 kHz for studying the horn’s performance using the Ansys workbench tool. Typically, the machining tool attached to the transducer through the horn vibrates at the amplitude level of 5–20 μm. However, for effective machining, the tool requires even more magnitude of amplitude level 50–150 μm of vibration within this frequency range. We directed the work towards innovative design method of ultrasonic horns with significant improvements over earlier reported works. Here the objective of the work is to obtain the optimum magnification factor (ratio of output to input amplitude of horn) within permissible stress limits. The standard criteria “Maximizing the magnification factor where the corresponding equivalent von-Mises stresses are within the permissible limit at a specified resonant frequency” is considered in the horn design to avoid failures of the tool and horn during machining. The optimum number of elements required for discretization in FEA and its identified to mitigate computational time based on the optimum mesh convergence criteria. In this study, the equivalent von-Mises stresses, and magnification factor of the horn are analyzed using Harmonic response analysis, which can use to arrive at effective machining processes. We have done the comparative study and validation of the newly designed horn’s performance with the existing horn designs at a similar input parameter or loading conditions.