On the use of a rounded sonotrode for the welding of thermoplastic composites

Continuous ultrasonic welding is an attractive welding technique for thermoplastic composite structures. In this process, a metallic sonotrode connected to a piezoelectric transducer and to a press moves along the parts to be welded applying ultrasonic vibrations and a static welding force on the welding overlap. Thus far, the research carried...

On improving process efficiency and weld quality in ultrasonic welding of misaligned thermoplastic composite adherends

This paper evaluates the potential of changing the welding force and the compliance of the energy director (ED) to reduce the effects caused by misaligned adherends, which were: increased through-thickness heating, reduced size of welded area and increased heating time. In the methodology that was followed, we welded adherends misaligned by...

Improving the quality of continuous ultrasonically welded thermoplastic composite joints by adding a consolidator to the welding setup

Continuous ultrasonic welding is a promising high-speed and energy-efficient joining technique for thermoplastic composite structures. However, in the current state-of-the-art research on the topic numerous deconsolidation voids could be identified at the welding interface, which results in a strength knock-down. The aim of this study is,...

A Study on Through-the-Thickness Heating in Continuous Ultrasonic Welding of Thermoplastic Composites

Continuous ultrasonic welding is a promising technique for joining thermoplastic composites structures together. The aim of this study was to gain further insight into what causes higher through-the-thickness heating in continuous ultrasonic welding of thermoplastic composites as compared to the static process. Thermocouples were used to measure...

On differences and similarities between static and continuous ultrasonic welding of thermoplastic composites

Continuous ultrasonic welding is a promising high-speed and energy-efficient joining method for thermoplastic composite structures. Our aim was to identify and understand differences between the static and continuous ultrasonic welding process for thermoplastic composites. In particular, melting of the interface, consumed power and energy...

Continuous ultrasonic welding of thermoplastic composites: Enhancing the weld uniformity by changing the energy director

Continuous ultrasonic welding is a high-speed joining method for thermoplastic composites. Currently, a thin film energy director is used to focus the heat generation at the interface. However, areas of intact energy director remain in the welded seam, which significantly lowers the weld strength, and result in a non-uniformly welded seam. To...

Gradient interphases between high-Tg epoxy and polyetherimide for advanced joining processes

Adhesive joining of carbon fibre reinforced polymer (CFRP) is cumbersome due to the careful surface preparation required and multiple validation steps to certify adhesion quality. Further these joints are often supplemented by mechanical fastenings add weight whilst also localising bearing stress. As an alternative technique, CFRP parts can be...

Improving weld uniformity in continuous ultrasonic welding of thermoplastic composites

Continuous ultrasonic welding (CUW) is an innovative high-speed joining method for thermoplastic composites. Currently, thin flat energy directors (EDs) are used to focus the heat generation at the weld line. The resulting fracture surfaces exhibit large areas of intact ED, resulting in a non-uniform weld, and significantly lowering the strength...