Tuesday, 26 March at 12h00

Bernal Seminar by Dr Irene Fernandez Villegas, Faculty of Aerospace Engineering, Delft University of Technology, The Netherlands


Ultrasonic Welding of Thermoplastic Composite Structures:

Past, Present and Future


Ultrasonic welding is a very interesting technique for the assembling of thermoplastic composite structures which offers very high production rates, low energy consumption and suitability for in situ process monitoring. Extensive research has been performed during the last decade at TU Delft to understand, mature and investigate fields of application for ultrasonic welding of thermoplastic composites. Some interesting results of that research, mostly carried out at coupon level, have been: definition and assessment of simplified energy directing concepts [1,2], definition of the relationship between process data and weld quality and, based on it, of an empirical procedure to obtain optimum welding parameters [3,4], definition and proof of concept of a sequential ultrasonic welding process [5], development and proof of concept of a continuous ultrasonic welding process [6], process modelling [7,8], performance of welded joints relative to traditional joints [9], and welding of thermoset composites [10]. Based on that knowledge, current work majorly focuses on the up-scaling of both sequential and continuous ultrasonic welding for the thermoplastic composite aircraft of the future. This presentation provides an overview of research on ultrasonic welding in the last decade as well as an outlook on future developments.

Villegas I.F., Valle Grande B., Bersee H.E.N., Benedictus R. A comparative evaluation between flat and traditional energy directors for ultrasonic welding of thermoplastic composites. Composite Interfaces 2015; 22(8): 717-729.

Palardy G., Villegas I.F. On the effect of flat energy director thickness on heat generation during ultrasonic welding of thermoplastic composites. Composite Interfaces 2017; 24(2): 203-214.

Villegas I.F. In situ monitoring of ultrasonic welding of thermoplastic composites through power and displacement data. Journal of Thermoplastic Composite Materials 2015; 28(1): 66-85.

Villegas I.F. Strength development versus process data in ultrasonic welding of thermoplastic composites with flat energy directors and its application to the definition of optimum processing parameters. Composites: Part A 2014; 65: 27-37.

Zhao T., Broek C., Palardy G., Villegas I.F., Benedictus R. Towards robust sequential ultrasonic spot welding of thermoplastic composites: Welding process control strategy for consistent weld quality. Composites Part A 2018: 109: 355-367.

Senders F., van Beurden M., Palardy G. Villegas I.F. Zero flow: a novel approach to continuous ultrasonic welding welding of CF/PPS thermoplastic composite plates. Advanced Manufacturing: Polymer and Composite Science 2016; 2(3-4): 83-92.

Levy A., Le Corre S., Villegas I.F. Modelling of the heating phenomena in ultrasonic welding of thermoplastic composites with flat energy directors. Journal of Materials Processing Technology 2014; 214: 1361-1371.

Palardy G., Shi H., Levy A., Le Corre S., Villegas I.F. A study on amplitude transmission in ultrasonic welding of thermoplastic composites. Composites Part A 2018: 113: 339-349.

Zhao T., Palardy G., Villegas I.F., Rans C., Martinez M., Benedictus R. Mechanical behaviour of thermoplastic composite spot-welded and mechanically fastened joints. Composites Part B 2016; 112: 224-234.

Villegas I.F., van Moorleghem R. Ultrasonic welding of carbon/epoxy and carbon/PEEK composites through a PEI thermoplastic coupling layer. Composites Part A 2018: 109: 75-83.



Irene Fernandez Villegas is an Associate Professor at the Faculty of Aerospace Engineering at Delft University of Technology. She got her MSc degree on Aerospace Engineering at the Polytechnic University of Madrid (UPM, Madrid, Spain) and her PhD degree at the same University on a dissertation entitled “Analysis of the resistance welding process for advanced thermoplastic composite materials”. During her career as a researcher (National Institute for Aerospace Technology, INTA, Madrid) and later as an academic (Delft University of Technology), she has accumulated more than 18 years of experience on polymer composite welding technologies. She has devoted a big part of these years to the understanding and development of ultrasonic welding of thermoplastic and of thermoset composites. She believes that welding is a key technology to reduce the environmental impact of aviation and she is passionate about pushing research to the limits of what is considered possible.


DATE:                    Tuesday, 26 March 2019

TIME:                    12h00

VENUE:                MSG-025 MSSI Building Extension


Tea/coffee will be available at 11h45

For further information, please contact:  ronan.ohiggins@ul.ie