Numerical and experimental investigation on the shapes of the sonotrode during ultrasonic welding

Ultrasonic welding is a revolutionary solid-state welding technique for joining metals as well as non-metals whereby high-frequency ultrasonic mechanical vibrations are locally applied to workpieces being held together under pressure. The high-frequency vibrations along with applied pressure create frictional heat at the mating surfaces leading to molecular bond. This work presents the effects of the different shapes of the sonotrode on the transient temperature distribution during the welding, using finite element analysis (FEA). The three different shapes of sonotrodes: stepped, conical and exponential are considered. Prepared FE models are capable of predicting the temperature distribution to different parts such as weld interface, sonotrode, and anvil. The results of the FE model are validated with experimental results using K-type thermocouple.