PSI - Issue 39

Aleksandar Grbovic et al. / Procedia Structural Integrity 39 (2022) 786–791 Author name / Structural Integrity Procedia 00 (2019) 000–000

790

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4-stringer

4-stringer with 3-clips

100 120 140 160 180 200

0 20 40 60 80

Crack length 2a (mm)

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100000 150000 200000 250000 300000

Number of cycles

Fig. 6. Crack length .vs. Number of cycles for panels with 4 stringers and with additional 3 clips.

4. Conclusions Based on the results presented in this paper, one can conclude that additional 3 clips do not contribute significantly to the increase of life of panel with 4 stringers. In other words, it is not justified to increase production costs with additional welding of 3 clips. Acknowledgements This research was supported by the Ministry of Sciences and Technology of Republic of Serbia through the contracts 451-03-9/2021-14/200105 and 451-03-68/2020 -14/200105. References 1. Bayraktar, F.S., Analysis of residual stress and fatigue crack propagation behaviour in laser welded aerospace aluminium T-joints, PhD thesis, Technischen Universität HamburgHarburg, 2011Braun, R., Dalle-Donne, C., Staniek, G. (2000). Laser beam and friction stir welding of 6013 T6 aluminium alloy sheet , Material-wissenschaft und Werkstofftechnik, 31(12): 1017-1026. 2. Proceeding of the GKSS/TWI Workshop on Friction Stir Welding, GKSS Research Center, Geesthacht, Germany, May 1999. 3. Sghayer, A., Grbović, A ., Sedmak, A., Dinulović, M., Doncheva, E., Petrovski, B., Fatigue life analysis of the integral skin-stringer panel using XFEM, Structural Integrity and Life, Vol. 17, p. 7-10, 2017 4. Djurdević A., Živojinović D., Grbović A., Sedmak A., Rakin M., Dascau H., Kirin S., Numerical simulatio n of fatigue crack propagation in friction stir welded joint made of Al 2024-T351 alloy, Engineering Failure Analysis, Volume 58, Pages 477–484, December 01, 2015 5. Kraedegh, A., Sedmak, A,. Grbovic, A., Sedmak, S., Stringer effect on fatigue crack propagation in A2024-T351 aluminum alloy welded joint, International Journal of Fatigue, Volume 105, December 2017, Pages 276-282 6. Sghayer, A., Grbović, A ., Sedmak, A., Dinulović, M ., Grozdanović, I ., Sedmak, S., Petrovski, B., Experimental and Numerical Analysis of Fatigue Crack Growth in Integral Skin-Stringer Panels, Technical gazette, Vol. 25, No. 3, 2018. 7. Munroe, J., Wilkins, K., Gruber, M., Integral Airframe Structures (IAS) - Validated Feasibility Study of Integrally Stiffened Metallic Fuselage Panels for Reducing Manufacturing Costs, NASA/CR-2000-209337, May 2000. 8. Grbović A., Sedmak A., Kastratović G., Petrašinović D., Vidanović N., Sghayer A., Effect of laser beam welded reinforcement o n integral skin panel fatigue life, Engineering Failure Analysis, Volume 101, Pages 383 – 393, July 2019