PSI - Issue 42

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

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

Procedia Structural Integrity 42 (2022) 967–976

© 2022 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 scientific committee of the 23 European Conference on Fracture – ECF23 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 Keywords: Back face strain; Compliance; FEM; SENB; Four point bending; DCPD; Strain gauge; Crack 1. Introduction The prediction of the (residual) life of a dynamically loaded steel structure depends on the proper understanding of crack growth behaviour. The fatigue life comprises different stages; (a) crack nucleation and initiation, (b) short crack growth and (c) long crack propagation up to failure. In the case of welded joints, the crack initiation stage is relatively short, and the major part of the lifetime is usually spent at short crack growth until it becomes a long crack (Hobbacher, extended applicati range in erms of relative rack length. FE simulations have been used to calibrate a back-face strain compliance equation for calculation of relative crack length in the range 0.05 ≤ / ≤ 0.5 for SENB-4P sp imens. Four point bending fatigue tests were performed on SENB specimens extracted from 50 mm thi welded st el plat s. Direct current potential drop (DCPD) for crack monitoring was used as benchmark and validation of the crack lengths determined from a back-face strain gage. © 2020 The Authors. Published by Elsevier B.V. This is an ope acces article under the CC BY-N -ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) P er-review under responsibility of 23 uropean C nfere ce o Fracture - ECF23 Keywords: Back face strain; Compliance; FEM; SENB; Four point bending; DCPD; Strain gauge; Crack 1. Introduction The prediction of the (residual) life of a dynamically loaded steel structure depends on the proper understanding of crack growth behaviour. The fatigue life comprises different stages; (a) crack nucleation and initiation, (b) short crack gr wth and (c) long crack propagation up to failure. In the case of welded joints, the crack initiation stage is relatively short, and the major part of the lifetime is usually spent at short crack growth until it becomes a long crack (Hobbacher, Abstract Compliance equations based on back-face strain or crack mouth opening displacement, and potential drop techniques are widely used to calculate fatigue crack growth rate. Standard ASTM E647 for fatigue crack growth rate testing does not include compliance based equations for single edge notched four-point bending (SENB-4P) specimens. Equations developed based on finite element (FE) analysis have been reported in literature; however, they are limited to the long crack propagation regime (i.e., relative crack length ratios ⁄ > 0.15 ). No compliance relations for crack growth in the physically short crack regime were found in literature. This work reports on a complementary numerical-experimental study towards the development of compliance equations with an extended application range in terms of relative crack length. FE simulations have been used to calibrate a back-face strain compliance equation for calculation of relative crack length in the range 0.05 ≤ / ≤ 0.5 for SENB-4P specimens. Four point bending fatigue tests were performed on SENB specimens extracted from 50 mm thick welded steel plates. Direct current potential drop (DCPD) for crack monitoring was used as benchmark and validation of the crack lengths determined from a back-face strain gage. Abstract Compliance equations based on back-f ce strain or crack mouth openin displacement, and potential drop techniqu s are widely used to calculate fatigue crack growt rate. Standard ASTM E647 for fatigu rack growth rate testing does not include compliance based equat ons for single edg notched four-point b nding (SENB-4P) specime s. Equations devel ped bas d on finite element (FE) an lysis have been reported in literature; however, they are limited to the long crack propagation r gime (i.e., relativ crack length ratios ⁄ > 0.15 ). No complia ce relations fo crack growth in the physically short crack regi e wer found in literature. This work reports a complem ntary numerical-experimental study tow rds the d velopment of compliance equations with a 23 European Conference on Fracture - ECF23 Calibration and validation of extended back-face strain compliance for a wide range of crack lengths in SENB-4P specimens Hasan Saeed a* , Somsubhro Chaudhuri a , Wim De Waele a 23 European Conference on Fracture - ECF23 Calibration and validation of extended back-face strain compliance for a wide range of crack lengths in SENB-4P specimens Hasan Saeed a* , Somsubhro Chaudhuri a , Wim De Waele a a Department of EMSME, Laboratory Soete, Faculty of Engineering and Architecture, Ghent University, Technologiepark 46, BE-9052 Zwijnaarde, Belgium a Department of EMSME, Laboratory Soete, Faculty of Engineering and Architecture, Ghent University, Technologiepark 46, BE-9052 Zwijnaarde, Belgium

* Corresponding author. Tel.: +32-494448392. E-mail address: hasan.saeed@ugent.be * Correspon ing author. Tel.: +32-494448392. E-mail address: hasan.saeed@ugent.be

2452-3216 © 2022 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 scientific committee of the 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.122 2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23