Issue 41

S. Seitl et alii, Frattura ed Integrità Strutturale, 41 (2017) 323-331; DOI: 10.3221/IGF-ESIS.41.43 323 Focused on Crack Tip Fields Williams expansion-based approximation of the stress field in an Al 2024 body with a crack from optical measurements S. Seitl, L. Malíková Brno University of Technology, Faculty of Civil Engineering, Institute of Structural Mechanics, Veveří 331/95, 602 00 Brno, Czech Republic and Academy of Sciences of the Czech Republic, Institute of Physics of Materials, v. v. i., Žižkova 22, 616 62 Brno, Czech Republic seitl@ipm.cz, http://orcid.org/0000-0002-4953-4324 malikova.l@fce.vutbr.cz , http://orcid.org/0000-0001-5868-5717 J. Sobek, P. Frantík Brno University of Technology, Faculty of Civil Engineering, Institute of Structural Mechanics, Veveří 331/95, 602 00 Brno, Czech Republic Sobek.j@fce.vutbr.cz , http://orcid.org/0000-0003-4215-1029 frantik.p@fce.vutbr.cz , P. Lopez-Crespo Department of Civil and Materials Engineering , University of Malaga, C/Dr Ortiz Ramos s/n, 29071 Malaga, Spain plopezcrespo@uma.es A BSTRACT . A study on the approximation of the stress field in the vicinity of crack tip in a compact tension specimen made from Al 2024-T351 is presented. Crack tip stress tensor components are expressed using the linear elastic fracture mechanics (LEFM) theory in this work, more precisely via its multi-parameter formulation, i.e. by Williams power series (WPS). Determination of coefficients of terms of this series is performed using a least squares-based regression technique known as over deterministic method (ODM) for which displacements data obtained experimentally via optical measurements are taken as inputs. The stress fields reconstructed based on the displacement data obtained experimentally by means of optical measurements are verified by means of the stress field approximations derived for the normalized CT specimen via hybrid elements. K EYWORDS . Crack tip fields; Optical measurements; DIC; Williams power series; Higher-order terms; Stress field reconstruction; Multi-parameter approximation . Citation: Seitl, S., Malíková, L., Sobek, J., Frantík, P., Lopez-Crespo P., Williams expansion-based approximation of the stress field in a Al2024 body with a crack from optical measurements, Frattura ed Integrità Strutturale, 41 (2017) 323-331. Received: 28.02.2017 Accepted: 03.05.2017 Published: 01.07.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.