Print Email Facebook Twitter Diagnostic of manufacturing defects in ultrasonically welded thermoplastic composite joints using ultrasonic guided waves Title Diagnostic of manufacturing defects in ultrasonically welded thermoplastic composite joints using ultrasonic guided waves Author Ochôa, Pedro (TU Delft Structural Integrity & Composites) Villegas, I.F. (TU Delft Aerospace Manufacturing Technologies) Groves, R.M. (TU Delft Structural Integrity & Composites) Benedictus, R. (TU Delft Structural Integrity & Composites) Date 2019 Abstract This article presents research about the propagation of ultrasonic guided waves in ultrasonically welded thermoplastic composite joints. The goal of the study was to understand the effect of weld manufacturing defects on guided wave transmission across the joint. Triangular energy-directors integrated into the lower composite adherends enabled the production of defective joints in a controlled manner. The produced defect types were unwelded areas and adherend fibre bundle distortion. The reference condition corresponded to the fully welded stage which showed the highest single-lap shear strength. It was possible to detect adherend fibre bundle distortion through the increase in the negative shift of the signal characteristic frequency. Evidence of the presence of unwelded areas was found in the increase of Time-of-Flight of the maximum amplitude Lamb wave group. The sensitivity of the diagnostic parameters was found to be dependent on the ultrasonic guided wave excitation frequency. Subject Manufacturing defectsStructural health monitoringThermoplastic compositeUltrasonic guided wavesUltrasonic welding To reference this document use: http://resolver.tudelft.nl/uuid:980bd084-e5a7-47b5-8222-6dde031fd96a DOI https://doi.org/10.1016/j.ndteint.2019.102126 Embargo date 2021-12-22 ISSN 0963-8695 Source NDT&E International, 107 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 © 2019 Pedro Ochôa, I.F. Villegas, R.M. Groves, R. Benedictus Files PDF 1_s2.0_S0963869518306017_main_1.pdf 2.72 MB Close viewer /islandora/object/uuid:980bd084-e5a7-47b5-8222-6dde031fd96a/datastream/OBJ/view