PSI - Issue 75

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia (2025) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia (2025) 000 – 000 Available online at www.sciencedirect.com Procedia Structural Integrity 75 (2025) 489–500

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2452-3216 © 2025 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 the responsibility of Dr Fabien Lefebvre with at least 2 reviewers per paper 10.1016/j.prostr.2025.11.049 2452-3216 © 2025 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 Fatigue Design 2025 organizers 2452-3216 © 2025 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 Fatigue Design 2025 organizers © 2025 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 the responsibility of Dr Fabien Lefebvre with at least 2 reviewers per paper The increased use of integral structures is critical for developing improved commercial transport structures and unmanned and manned space transport. They reduce the use of rivets and the need to create lap joints, the primary source location of multi site fatigue damage, especially in airframe structures. One method being examined is to produce and join large modular units by welding. Welding is crucial in aerospace applications, construction, and automotive industries. Nevertheless, welds are sensitive to fatigue failure due to cyclic loading and fatigue crack propagation influenced by welding residual stresses (RS) distribution. Residual stress in welding is mainly the result of thermal expansion, which, in basic terms, means that weld metal and parent material expand or contract with temperature changes, and they can be very high up to the yield strength of the material. Residual stress can cause failure in welds by leading to fatigue structural damage. The fatigue life of the welding can be increased by machining the weld bead to reduce from higher to lower tensile residual stress, and compressive residual stresses in the weld bead are removed. This research analyses the fatigue strength developed by a robotic welding process and subsequent machining of the weld bead through a control numerical process in duplex stainless steel 2205 (DSS). Two main variables will be studied: i) heat input as a welding variable and ii) chip cross-sectional area as a machining variable. Results showed that X-ray diffraction measurement along the centre thickness of the machined welded plates reveals compressive residual stress near the adjacent weld region, and the fatigue properties of the machined weldment are enhanced by 80% at 550 MPa and 92% at 350 MPa compared to the DSS welds with the weld bead . Keywords: Fatigue strength; residual stress; robotic welding; duplex stainless steel. The increased use of integral structures is critical for developing improved commercial transport structures and unmanned and manned space transport. They reduce the use of rivets and the need to create lap joints, the primary source location of multi site fatigue damage, especially in airframe structures. One method being examined is to produce and join large modular units by welding. Welding is crucial in aerospace applications, construction, and automotive industries. Nevertheless, welds are sensitive to fatigue failure due to cyclic loading and fatigue crack propagation influenced by welding residual stresses (RS) distribution. Residual stress in welding is mainly the result of thermal expansion, which, in basic terms, means that weld metal and parent material expand or contract with temperature changes, and they can be very high up to the yield strength of the material. Residual stress can cause failure in welds by leading to fatigue structural damage. The fatigue life of the welding can be increased by machining the weld bead to reduce from higher to lower tensile residual stress, and compressive residual stresses in the weld bead are removed. This research analyses the fatigue strength developed by a robotic welding process and subsequent machining of the weld bead through a control numerical process in duplex stainless steel 2205 (DSS). Two main variables will be studied: i) heat input as a welding variable and ii) chip cross-sectional area as a machining variable. Results showed that X-ray diffraction measurement along the centre thickness of the machined welded plates reveals compressive residual stress near the adjacent weld region, and the fatigue properties of the machined weldment are enhanced by 80% at 550 MPa and 92% at 350 MPa compared to the DSS welds with the weld bead . Keywords: Fatigue strength; residual stress; robotic welding; duplex stainless steel. Fatigue Design 2025 (FatDes 2025) Fatigue strength improvement by machining process in stainless steel welds Carolina Payares -Asprino a * , Christian Félix Martínez b , Ulises Sánchez Santana b , Sean Meese a Fatigue Design 2025 (FatDes 2025) Fatigue strength improvement by machining process in stainless steel welds Carolina Payares -Asprino a * , Christian Félix Martínez b , Ulises Sánchez Santana b , Sean Meese a a Norwich University, Mechanical Engineering Department, 158 Harmon Drive, Northfield, VT 05663, USA b CIDESI, Centro de Ingeniería y Desarrollo Industrial, Desarrollo San Pablo, 76125, Santiago de Querétaro, México a Norwich University, Mechanical Engineering Department, 158 Harmon Drive, Northfield, VT 05663, USA b CIDESI, Centro de Ingeniería y Desarrollo Industrial, Desarrollo San Pablo, 76125, Santiago de Querétaro, México Abstract * Corresponding author. Tel.: +1-802-485-2281 E-mail address: mpayares@norwich.edu Abstract * Corresponding author. Tel.: +1-802-485-2281 E-mail address: mpayares@norwich.edu