Final Thesis

Understanding how acoustic waves travel in a solid for Ultrasonic Metal Welding

This thesis is about understanding how acoustic waves (a.k.a vibrations) travel in a solid, and using that to improve the production of batteries for electric cars are made.

Ultrasonic Metal Welding (USMW) is used to weld electronics. The concept is simple: two metal sheets are pressed and rubbed against each other at 20 kHz. Due to friction, the plates are welded together. However, the quality of the weld fluctuates from process to process. During our experiments, we have seen that the Anvil, one of the major parts of the welding machine, vibrates with specific patterns correlated to the strength of the weld. Currently, we are monitoring the process by measuring the vibrations of the anvil using a laser.

The goal of this project is to understand how the vibrations travel from the welding area to the measurement point, and how they affect the acoustic waves. This will be done using simulations on the software COMSOL. If needed and wanted by the student, it is also possible to run new measurements in the 4th month of the thesis, for new validation of the simulations.

In this thesis, you will learn about:
- acoustic and general simulation skills (needed for all fields of work, including all fields of acoustics);
- transfer path analysis (very used in the industry, for example the automobile industry, or building acoustics);
- validation of simulations with experimental data;
- setting a work plan, structuring your work, presenting your results effectively.