PSI - Issue 28

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.co ci c ir ct Structural Integrity Procedia 00 (2019) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 28 (2020) 1590–1600

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Using backface strain gauge is a very common technique for structural health monitoring in the adhesively bonded joints while loading. Finite Element (FE) techniques used for failure prediction of such joints are normally validated against failure load not strain measurements. However, backface strain measurement can be highly influenced by different parameters (such as tolerance in the thickness of the bondline, strain gauge misalignment, etc.). In this work, the applicability of a new location for placing the back-face strain gauges on the adhesively bonded single lap joints (SLJs) for damage detection is examined. This location is based on the undamaged (healthy) state of the joint and is independent of the applied load. SLJs were tested under quasi static tension loading. FE models were developed for validating the variation of longitudinal strain on the bondline of the joint against experimental tension quasi-static tests. The influence of different parameters -which are inevitable in the assembly process and testing the joint- on strain measurement is investigated. © 2020 The Authors. Published by ELSE IER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Keywords: joint design, finite element stress analysis, fracture, adhesive, damage monitoring, strain gauge, SHM 1st irtual uropean onference on Fracture Experimental and FE investigations on the influential parameters in siti i s r t f str i s i si l si l l j i ts M. . adeghi a, *, J. eiland b , J. i er ann a , . chiebahn b , . eisgen b , . . chröder a a Institute of Structural Mechanics and Lightweight Design, RWTH Aachen University, Wuellnerstrasse 7, 52062 Aachen, Germany b Welding and Joining Institute, RWTH Aachen University, Pontstrasse 49, 52068, Aachen, Germany Abstract Using backface strain gauge is a very common technique for structural health monitoring in the adhesively bonded joints while loading. Finite Element (FE) techniques used for failure prediction of such joints are normally validated against failure load not strain measurements. However, backface strain measurement can be highly influenced by different parameters (such as tolerance in the thickness of the bondline, strain gauge misalignment, etc.). In this work, the applicability of a new location for placing the back-face strain gauges on the adhesively bonded single lap joints (SLJs) for damage detection is examined. This location is based on the undamaged (healthy) state of the joint and is independent of the applied load. SLJs were tested under quasi static tension loading. FE models were developed for validating the variation of longitudinal strain on the bondline of the joint against experimental tension quasi-static tests. The influence of different parameters -which are inevitable in the assembly process and testing the joint- on strain measurement is investigated. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Keywords: joint design, finite element stress analysis, fracture, adhesive, damage monitoring, strain gauge, SH 1st Virtual European Conference on Fracture Experimental and FE investigations on the influential parameters in positioning and measurement of strain gauges in adhesively bonded single lap joints M. Z. Sadeghi a, *, J. Weiland b , J. Zimmermann a , A. Schiebahn b , U. Reisgen b , K. U. Schröder a a Institute of Structural Mechanics and Lightweight Design, RWTH Aachen University, Wuellnerstrasse 7, 52062 Aachen, Germany b Welding and Joining Institute, RWTH Aachen University, Pontstrasse 49, 52068, Aachen, Germany Abstract

* Corresponding author. Tel.: +49-241-80 96837; fax: + 49-241-80 96837. E-mail address: zamaan.sadeghi@sla.rwth-aachen.de * Corresponding author. Tel.: +49-241-80 96837; fax: + 49-241-80 96837. E-mail address: zamaan.sadeghi sla.rwth-aachen.de

2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.10.131