Sonic weld characterization and FEA modeling method development for automotive applications

Joining is a critical part of any structure for transferring load and maintaining integrity for the product. Ultrasonic weld is one of the popular methods for joining plastic parts in automotive industry. Along with providing a visually demanding finish, the method has been established for tight, strong, and dimensionally accurate joints. With the increase of complexity and integration of electrical and sensing instrumentation in autonomous and electric vehicles, sonic weld provides a necessary means of attaching plastic parts without compromising visual impact. However, the sonic weld performance is yet to be quantified, and the criteria for capturing weld separation, and losing this connected load path during structural vehicle analysis, has not been studied extensively. Sonic welds, even though it is a very effective joining method, the whole tooling process is expensive and time consuming. Ideally, to optimize the welding spot number and develop future cost-effective welding methods, it is crucial to understand the actual weld performance under several variables such as material type, temperature, strain rates, etc.