PSI - Issue 28

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 28 (2020) 2195–2205

© 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 Abstract Experiments to describe the crack growth behavior are expensive and complex, while the evaluation depends mainly on the determined crack lengths over the testing period. Digital image correlation (DIC) is well established for crack-length and displacement measurements, but it normally requires sample preparation with speckle paint and interferes with mechanical extensometers. Novel GPU-based DIC system capable of measuring total strain at rates up to 850 Hz and strain-fields overcome these limitations. We present first results of fatigue crack growth experiments with uniaxially und biaxially loaded specimens. The force controlled tests under room-temperature conditions were accompanied by conventional measuring systems comprising a side extensometer, an ACPD-measurement system and the GPU-based DIC system. The results indicate that DIC-measured crack depth correlates well with ACPD crack depth values. Furthermore, the crack-flank displacements derived from DIC-evaluation are in good agreement with 2D-FEM simulations. The GPU-based DIC-System appears as a promising measurement technique for crack growth investigations. © 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: Digital image correlation; Fatigue crack growth; Uni- and biaxial loading 1. Introduction Components experience multiaxial loading conditions in most cases due to external forces or the geometrical shape of the part, which is mostly neglected when fracture mechanical assessment are performed. Instead, the assessment is 1st Virtual European Conference on Fracture GPU-based digital image correlation system for uniaxial and biaxial crack growth investigations F. Conrad a,* , A. Blug b , J. Kerl a , J. Fehrenbach b,c , D. J. Regina b , A. Bertz b , C. Kontermann a , D. Carl b , M. Oechsner a a Technical University of Darmstadt ,Chair and Institute for Materials Technology IfW, Grafenstrasse 2, 64283 Darmstadt, Germany b Fraunhofer Institute for Physical Measurement Techniques IPM, Georges-Koehler-Allee 301, 79110 Freiburg, Germany c Saarland University of Applied Sciences, Goebenstraße 40, 66117 Saarbruecken, Germany

* Corresponding author. Tel.: +49-6151-16-25316; fax: +49-6151-16-25122. E-mail address: conrad@mpa-ifw.tu-darmstadt.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 10.1016/j.prostr.2020.11.048