PSI - Issue 38

A. Chiocca et al. / Procedia Structural Integrity 38 (2022) 447–456

455

A. Chiocca et al. / Structural Integrity Procedia 00 (2021) 000–000

9

5. Conclusion

In this paper, results of the experimental and numerical influence of residual stresses on the fatigue life of welded joints and notched specimens were reported. In order to better understand the outcomes obtained from the welded joints, an exploratory study was carried out on a simpler notched specimen geometry, in presence of a compressive preload. From the analysis conducted it can be concluded that: • the thermal-structural model implemented, although simplified, allows the simulation of the welding process and thus enables to understand the numerical e ff ect of residual stresses on the fatigue life of the welded joint; • residual stresses showed a larger e ff ect on fatigue life if a pure torsion load is considered rather than a pure bending load; • if stress triaxiality is considered as a fatigue damage factor, a higher di ff erence between as-welded and stress relieved specimen is found by implementing pure torsion loading; in facts, torsion load alone is not able to alter the hydrostatic stress field produced by the initial residual stresses. [1] Ansaripour, N., Heidari, A., Eftekhari, S.A., 2020. Multi-objective optimization of residual stresses and distortion in submerged arc welding process using Genetic Algorithm and Harmony Search. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, 862–871. doi: 10.1177/0954406219885977 . [2] Barsoum, Z., Barsoum, I., 2009. Residual stress e ff ects on fatigue life of welded structures using LEFM. Engineering Failure Analysis 16, 449–467. doi: 10.1016/j.engfailanal.2008.06.017 . [3] Bartolozzi, R., Frendo, F., 2011. Sti ff ness and strength aspects in the design of automotive coil springs for McPherson front suspensions: A case study. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 225, 1377–1391. doi: 10.1177/ 0954407011403853 . [4] Bertini, L., Cera, A., Frendo, F., 2014. Experimental investigation of the fatigue resistance of pipe-to-plate welded connections under bending, torsion and mixed mode loading. International Journal of Fatigue 68, 178–185. doi: 10.1016/j.ijfatigue.2014.05.005 . [5] Bertini, L., Frendo, F., Marulo, G., 2016. E ff ects of plate sti ff ness on the fatigue resistance and failure location of pipe-to-plate welded joints under bending. International Journal of Fatigue 90, 78–86. doi: 10.1016/j.ijfatigue.2016.04.015 . [6] Bhatti, A.A., Barsoum, Z., Murakawa, H., Barsoum, I., 2015. Influence of thermo-mechanical material properties of di ff erent steel grades on welding residual stresses and angular distortion. Materials and Design 65, 878–889. doi: 10.1016/j.matdes.2014.10.019 . [7] Capriccioli, A., Frosi, P., 2009. Multipurpose ANSYS FE procedure for welding processes simulation. Fusion Engineering and Design 84, 546–553. doi: 10.1016/j.fusengdes.2009.01.039 . [8] Chiocca, A., Frendo, F., Bertini, L., 2019a. Evaluation of heat sources for the simulation of the temperature distribution in gas metal arc welded joints. Metals 9, 1142. doi: 10.3390/met9111142 . [9] Chiocca, A., Frendo, F., Bertini, L., 2019b. Evaluation of residual stresses in a tube-to-plate welded joint. MATEC Web of Conferences 300, 19005. doi: 10.1051/matecconf/201930019005 . [10] Chiocca, A., Frendo, F., Bertini, L., 2020. Experimental evaluation of relaxed strains in a pipe-to-plate welded joint by means of incremental cutting process. Procedia Structural Integrity 28, 2157–2167. doi: 10.1016/j.prostr.2020.11.043 . [11] Chiocca, A., Frendo, F., Bertini, L., 2021. Evaluation of residual stresses in a pipe-to-plate welded joint by means of uncoupled thermal-structural simulation and experimental tests. International Journal of Mechanical Sciences 199, 106401. doi: 10.1016/j.ijmecsci.2021.106401 . [12] Chlup, Z., Novotna´, L., Sˇ isˇka, F., Drdl´ık, D., Hadraba, H., 2020. E ff ect of residual stresses to the crack path in alumina / zirconia laminates. Journal of the European Ceramic Society 40, 5810–5818. doi: 10.1016/j.jeurceramsoc.2020.06.044 . [13] Ferro, P., Berto, F., 2016. Quantification of the Influence of Residual Stresses on Fatigue Strength of Al-Alloy Welded Joints by Means of the Local Strain Energy Density Approach. Strength of Materials 48, 426–436. doi: 10.1007/s11223-016-9781-0 . [14] Frendo, F., Bertini, L., 2015. Fatigue resistance of pipe-to-plate welded joint under in-phase and out-of-phase combined bending and torsion. International Journal of Fatigue 79, 46–53. doi: 10.1016/j.ijfatigue.2015.04.020 . [15] Frendo, F., Marulo, G., Chiocca, A., Bertini, L., 2020. Fatigue life assessment of welded joints under sequences of bending and torsion loading blocks of di ff erent lengths. Fatigue and Fracture of Engineering Materials and Structures 43, 1290–1304. doi: 10.1111/ffe.13223 . [16] Greß, T., Glu¨ck Nardi, V., Schmid, S., Hoyer, J., Rizaiev, Y., Boll, T., Seils, S., Tonn, B., Volk, W., 2021. Vertical continuous compound casting of copper aluminum bilayer rods. Journal of Materials Processing Technology 288, 116854. doi: 10.1016/j.jmatprotec.2020.116854 . [17] Hemmesi, K., Mallet, P., Farajian, M., 2020. Numerical evaluation of surface welding residual stress behavior under multiaxial mechanical loading and experimental validations. International Journal of Mechanical Sciences 168, 105127. doi: 10.1016/j.ijmecsci.2019.105127 . [18] Le, T., Paradowska, A., Bradford, M.A., Liu, X., Valipour, H.R., 2020. Residual stresses in welded high-strength steel I-Beams. Journal of Constructional Steel Research 167, 105849. doi: 10.1016/j.jcsr.2019.105849 . [19] Lillema¨e, I., Lammi, H., Molter, L., Remes, H., 2012. Fatigue strength of welded butt joints in thin and slender specimens. International Journal of Fatigue 44, 98–106. doi: 10.1016/j.ijfatigue.2012.05.009 . References