Print Email Facebook Twitter Experimental assessment of the influence of welding process parameters on Lamb wave transmission across ultrasonically welded thermoplastic composite joints Title Experimental assessment of the influence of welding process parameters on Lamb wave transmission across ultrasonically welded thermoplastic composite joints Author Ochôa, Pedro (TU Delft Structural Integrity & Composites) Villegas, I.F. (TU Delft Structural Integrity & Composites) Groves, R.M. (TU Delft Structural Integrity & Composites) Benedictus, R. (TU Delft Aerospace Structures & Materials; TU Delft Structural Integrity & Composites) Department Aerospace Structures & Materials Date 2018 Abstract One of the advantages of thermoplastic composites relative to their thermoset counterparts is the possibility of assembling components through welding. Ultrasonic welding in particular is very promising for industrialization. However, uncertainty in the fatigue and fracture behaviour of composites is still an obstacle to the full utilisation of these materials. Health monitoring is then of vital importance, and Lamb wave techniques have been widely recognised as some of the most promising approaches for that end. This paper presents the first experimental study about the influence of welding travel on the transmission of Lamb waves across ultrasonically welded thermoplastic composite joints in single-lap configuration. The main aim of this research is to start to understand how guided waves interact with the internal structure of ultrasonic welds, so that benign, manufacturing-related structural features can be distinguished from damaging ones in signal interpretation. The power transmission coefficient and the correlation coefficient proved to be suitable for analysing the wave propagation phenomena, allowing quantitative identification of small variations of weld-line thickness and intermolecular diffusion at the weld interface. The conclusions are used to develop a tentative damage detection criterion which can later on assist the design of a Lamb wave based structural health monitoring system for thermoplastic composite structures. The Lamb wave test results are backed up by phased-array inspections, which also provide some extra insight on the internal structure of ultrasonic welds. Subject Lamb waveStructural health monitoringThermoplastic compositeUltrasonic welding To reference this document use: http://resolver.tudelft.nl/uuid:a40335a3-0b7a-4c25-bded-719dcd10ff17 DOI https://doi.org/10.1016/j.ymssp.2017.06.009 Embargo date 2021-12-22 ISSN 0888-3270 Source Mechanical Systems and Signal Processing, 99, 197-218 Bibliographical note Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2018 Pedro Ochôa, I.F. Villegas, R.M. Groves, R. Benedictus Files PDF 1_s2.0_S0888327017303230_main_1.pdf 4.34 MB Close viewer /islandora/object/uuid:a40335a3-0b7a-4c25-bded-719dcd10ff17/datastream/OBJ/view