PSI - Issue 54

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ

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Procedia Structural Integrity 54 (2024) 585–592

© 2023 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 ICSI 2023 organizers Abstract The stress distribution in flat plates containing cracks and subjected to a uniform remote membrane or bending stress field shows that some zones refer to a high stress concentration compared with nominal values; while conversely, some other zones have almost negligible stresses, as a result of the redistribution of internal forces. Those zones, with a small or residual stress field, can be ignored in the model of the numerical simulation, as in such zones the material does not practically contribute to the structure stiffness. The removal of such Stress “Dead” Zones ( SDZ ), usually close to the crack mating faces, translates into a useful simplification in the structure shape model. This modified geometry supports the implementation of simple analytical algorithms in the evaluation of stiffness factors necessary for the computation of the associate stress-intensity factor (SIF) along the crack line. The accuracy of such models depends mainly on a precise delimitation of the SDZ at crack vicinity in the structural member. To ensure such precision, Digital Image Correlation was used to achieve reliable results for the SDZ delimitation areas. © 2023 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 ICSI 2023 organizers Keywords: Line-spring model; Stress Dead Zone; Part-Through Crack; Fracture Mechanics; International Conference on Structural Integrity 2023 (ICSI 2023) The Stress Dead Zones in the formulation of the Line Spring Model Francisco Q. de Melo, Vasco Amorim, Hugo Mesquita, Francisco Afonso, Paulo Tavares, Pedro M. G. P. Moreira INEGI, Institute of Science and Innovation in Mechanical Engineering and Industrial Engineering, Campus da FEUP, R. Dr. Roberto Frias 400, 4200-465 Porto, Portugal.

1. Line-Spring Model: history and essential concepts 1.1. Structure

The Line spring model is a structural concept to approach the deformation behavior of the remaining ligament in the plane of a part-through crack existing in a plate or shell. It was proposed by J. Rice and N. Levy (Rice and Levy 1972), where the remaining ligament in the part-through crack plane is replaced by a stack of thin blades, each of them having a side edge crack with variable depth, as shown in Figure 1. The part-through crack is then equivalent to a through crack where over its plane there is a set of thin blades with a variable depth side edge crack, reconstructing

2452-3216 © 2023 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 ICSI 2023 organizers

2452-3216 © 2023 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 ICSI 2023 organizers 10.1016/j.prostr.2024.01.122