Effect of Cracked and Notched Stiffeners on the Ultimate Strength of Steel Stiffened Panels

Abstract

This paper numerically evaluates the effect of the crack position on the ultimate strength of stiffened panels. Imperfections such as notches and cracks in aged marine stiffened panels can reduce their ultimate strength. To investigate the effect of crack length and position, a series of nonlinear finite element analyses were carried out and two cases were considered, i. e., case 1 with thin stiffeners and case 2 with thick stiffeners. In both cases, the stiffeners have the same cross-section area. To have a basis for comparison, the intact panels were modeled as well. The cracks and notches were in the longitudinal and transverse direction and were assumed to be in the middle part of the panel. The cracks and notches were assumed to be through the thickness and there is neither crack propagation nor contact between crack faces. Based on the numerical results, longitudinal cracks affect the behavior of the stiffened panels in the postbuckling region. When the stiffeners are thinner, they buckle first and provide no reserved strength after plate buckling. Thus, cracks in the stiffeners do not affect the ultimate strength in the case of the thinner stiffeners. Generally, when stiffeners are thicker, they affect the postbuckling behavior more. In that case, cracks in the stiffeners affect the buckling and failure modes of the stiffened panels. The effect of notch was also studied. In contrast to the longitudinal crack in stiffeners, a notch in the stiffeners reduces the ultimate strength of the stiffened panel for both slender and thick stiffeners.

Keywords

Stiffened panels / Crack / Notch / Ultimate strength / Buckling / Nonlinear finite element method

References

[] Aalberg A, Langseth M, Larsen P. Stiffened aluminium panels subjected to axial compression. Thin-Walled Struct, 2001, 39(10): 861-885,

[] Anyfantis KN. Ultimate strength of stiffened panels subjected to non-uniform thrust. Int J Nav Archit, 2020, 12: 325-342,

[] Babazadeh A, Khedmati MR. Ultimate strength of cracked ship structural elements and systems: A review. Eng Fail Anal, 2018, 89: 242-257,

[] Babazadeh A, Khedmati MR. Empirical formulations for estimation of ultimate strength of cracked continuous unstiffened plates used in ship structure under in-plane longitudinal compression. Eng Fail Anal, 2019, 100: 470-484,

[] Bayatfar A, Khedmati MR, Rigo P. Residual ultimate strength of cracked steel unstiffened and stiffened plates under longitudinal compression. Thin-Walled Struct, 2014, 84: 378-392,

[] Brighenti R. Buckling of cracked thin-plates under tension or compression. Thin-Walled Struct, 2005, 43(2): 209-224,

[] Cui C, Yang P, Xia T, Du J. Assessment of residual ultimate strength of cracked steel plates under longitudinal compression. Ocean Eng, 2016, 121: 174-183,

[] Cui C, Yang P, Li C, Xia T. Ultimate strength characteristics of cracked stiffened plates subjected to uniaxial compression. Thin-Walled Struct, 2017, 113: 27-38,

[] Fujikubo M, Harada M, Yao T, Khedmati MR, Yanagihara D. Estimation of ultimate strength of continuous stiffened panel under combined transverse thrust and lateral pressure Part 2: Continuous stiffened panel. Marine Structures, 2005, 18(5–6): 411-427,

[] Fujikubo M, Yao T, Khedmati MR, Harada M, Yanagihara D. Estimation of ultimate strength of continuous stiffened panel under combined transverse thrust and lateral pressure Part 1: Continuous plate. Marine Structures, 2005, 18(5–6): 383-410,

[] Ghavami K, Khedmati MR. Numerical and experimental investigations on the compression behaviour of stiffened plates. J Constr Steel Res, 2006, 62(11): 1087-1100,

[] Han P, Ri K, Yun C, Pak C, Paek S. A study on the residual ultimate strength of continuous stiffened panels with a crack under the combined lateral pressure and in-panel compression. Ocean Eng, 2021, 234: 109265,

[] Hosseinabadi OF, Khedmati MR, Norouzipoor M. Statistical analysis of initial deflection of aluminium plating between stiffeners. Thin-Walled Struct, 2021, 161: 107528,

[] Ikeda K, Murota K (2022) Bifurcation and Buckling in Structures. 2021: CRC Press. https://doi.org/10.1201/9781003112365

[] Khedmati MR, Rastani M. Nonlinear elastoplastic behaviour of intermittently welded stiffened plates under inplane compression. Proc Int Conf Offshore Mech Arct Eng-OMAE, 2006, 92603: 853-864,

[] Khedmati MR, Edalat P, Javidruzi M. Sensitivity analysis of the elastic buckling of cracked plate elements under axial compression. Thin-Walled Struct, 2009, 47(5): 522-536,

[] Khedmati MR, Zareei MR, Rigo P. Empirical formulations for estimation of ultimate strength of continuous stiffened aluminium plates under combined in-plane compression and lateral pressure. Thin-Walled Struct, 2010, 48(3): 274-289,

[] Khedmati MR, Nouri Zhme, Roshanali MM. A comparative computational investigation on the effects of randomly distributed general corrosion on the post-buckling behaviour of uniaxially loaded plates. Journal of mechanical science and technology, 2012, 26: 767-783,

[] Kim UN, Choe IH, Paik JK. Buckling and ultimate strength of perforated plate panels subject to axial compression: experimental and numerical investigations with design formulations. Sh Offshore Struct, 2009, 4(4): 337-361,

[] Li S, Kim DK, Benson S. The influence of residual stress on the ultimate strength of longitudinally compressed stiffened panels. Ocean Eng, 2021, 231: 108839,

[] Liu D, Hao P, Zhang K, Tian K, Wang B, Li G, Xu W. On the integrated design of curvilinearly grid-stiffened panel with nonuniform distribution and variable stiffener profile. Mater Des, 2020, 190: 108556,

[] Margaritis Y, Toulios M. The ultimate and collapse response of cracked stiffened plates subjected to uniaxial compression. Thin-Walled Struct, 2012, 50(1): 157-173,

[] Ozdemir M, Ergin A, Yanagihara D, Tanaka S, Yao T. A new method to estimate ultimate strength of stiffened panels under longitudinal thrust based on analytical formulas. Mar Struct, 2018, 59: 510-535,

[] Paik JK. Residual ultimate strength of steel plates with longitudinal cracks under axial compression-experiments. Ocean Eng, 2008, 35(17–18): 1775-1783,

[] Paik JK. Residual ultimate strength of steel plates with longitudinal cracks under axial compression—nonlinear finite element method investigations. Ocean Eng, 2009, 36(3–4): 266-276,

[] Putranto T, Kõrgesaar M, Jelovica J, Tabri K, Naar H. Ultimate strength assessment of stiffened panel under uni-axial compression with non-linear equivalent single layer approach. Mar Struct, 2021, 78: 103004,

[] Shaw D, Huang Y. Buckling behavior of a central cracked thin plate under tension. Eng Fract Mech, 1990, 35(6): 1019-1027,

[] Shi XH, Zhang J, Soares CG. Experimental study on collapse of cracked stiffened plate with initial imperfections under compression. Thin-Walled Struct, 2017, 114: 39-51,

[] Song ZJ, Xu MC, Moan T, Pan J. Dimensional and similitude analysis of stiffened panels under longitudinal compression considering buckling behaviours. Ocean Eng, 2019, 187: 106188,

[] Ueda Y, Yao T. The influence of complex initial deflection modes on the behaviour and ultimate strength of rectangular plates in compression. Journal of Constructional Steel Research, 1985, 5(4): 265-302,

[] Xia T, Yang P, Hu K, Cui C. Combined effect of imperfections on ultimate strength of cracked plates under uniaxial compression. Ocean Eng, 2018, 150: 113-123,

[] Xu MC, Soares CG. Assessment of the ultimate strength of narrow stiffened panel test specimens. Thin-Walled Struc, 2012, 55: 11-21,

[] Yao T, Nikolov P, Miyagawa Y. Karlsson L, Lindgren LE, Jonsson M. Influences of welding imperfections on stiffness of rectangular plate under thrust. mechanical effects of welding. Mechanical Effects of Welding. International Union of Theoretical and Applied Mechanics, 1992 Berlin, Heidelberg Springer

[] Yu CL, Chen YT, Yang S, Liu Y, Lu GC. Ultimate strength characteristic and assessment of cracked stiffened panel under uniaxial compression. Ocean Eng, 2018, 152: 6-16,

[] Zhang J, Shi XH, Soares CG, Liu J. Ultimate strength of stiffened panels with a crack and pits under uni-axial longitudinal compression. Sh Offshore Struct, 2022, 17(2): 319-338,

[] Zhang S, Khan I. Buckling and ultimate capability of plates and stiffened panels in axial compression. Mar Struct, 2009, 22(4): 791-808,