Numerical Investigation on the Effect of Material Inhomogeneity of Welded Joints on the Local Stress and Strain

Abstract

Welded joints can be divided into different material zones, with considerable variation of material properties around the weld toe. The material inhomogeneity influences the local stress and strain of welded joints under monotonic and cyclic loading. This study aims to examine the local stress and strain characteristics of welded joints considering material inhomogeneity. Numerical models with various material zones were developed, and material properties were determined based on hardness. Smooth specimen models were used to analyze stress and strain distributions excluding notch effects. A detailed inhomogeneous model of a welded joint was established based on extensive microhardness measurements around the weld toe and the Kriging interpolation method. Additionally, a homogeneous model and a simplified inhomogeneous model, based on limited measured data, were generated and compared with the detailed inhomogeneous model. Fatigue life was estimated using the Smith, Watson, and Topper method based on the obtained stress and strain. For smooth specimen models, stress concentration occurs at a location where the strain is not significant, and fatigue cracks were most likely to initiate from the base metal. Results from the two simplified models showed deviations from those of the detailed inhomogeneous model, and the limitations of these simplified models are discussed.

Keywords

Material inhomogeneity / Welded joints / Hardness / Local stress and strain

References

[1] ANSYS (2012) Online Manuals

[2] Basan R, Franulović M, Smokvina Hanza S. Estimation of cyclic stress-strain curves for low-alloy steel from hardness. Metalurgija, 2010, 49(2): 83-86

[3] Besel Y, Besel M, Dietrich E, Wischek J, Mercado UA, Kakiuchi T, Uematsu Y. Heterogeneous local straining behavior under monotonic and cyclic loadings in a friction stir welded aluminum alloy. International Journal of Fatigue, 2019, 125: 138-148.

[4] Dong Y, Garbatov Y, Guedes Soares C. Fatigue strength assessment of an annealed butt welded joint accounting for material inhomogeneity. Progress in the Analysis and Design of Marine Structures, 2017349-359.

[5] Dong Y, Teixeira A, Guedes Soares C. Application of adaptive surrogate models in time-variant fatigue reliability assessment of welded joints with surface cracks. Reliability Engineering & System Safety, 2020, 195: 106730.

[6] Dong Y, Garbatov Y, Guedes Soares C. Recent Developments in Fatigue Assessment of Ships and Offshore Structures. Journal of Marine Science and Application, 2022, 21(4): 3-25.

[7] Easterling K. Introduction to the physical metallurgy of welding, 2013

[8] Ezer MA, Çam G. A study on microstructure and mechanical performance of gas metal arc welded AISI 304 L joints. Materialwissenschaft und Werkstofftechnik, 2022, 53(9): 1043-1052.

[9] Gaspar B, Teixeira AP, Guedes Soares C. Assessment of the efficiency of Kriging surrogate models for structural reliability analysis. Probabilistic Engineering Mechanics, 2014, 37: 24-34.

[10] Hobbacher A. Recommendations for fatigue design of welded joints and components, 2015

[11] Kucharczyk P, Madia M, Zerbst U, Schork B, Gerwien P, Münstermann S. Fracture-mechanics based prediction of the fatigue strength of weldments. Material aspects. Engineering Fracture Mechanics, 2018, 198: 79-102.

[12] Lopez Z, Fatemi A. A method of predicting cyclic stress–strain curve from tensile properties for steels. Materials Science and Engineering, 2012, 556: 540-550.

[13] Maddox SJ. Fatigue strength of welded structures, 1991

[14] Madia M, Zerbst U, Beier HT, Schork B. The IBESS model–Elements, realisation and validation. Engineering Fracture Mechanics, 2018, 198: 171-208.

[15] Mallieswaran K, Rajendran C, Padmanabhan R, Rajasekaran S. Evaluation of nickel shot peening process on strength of friction stir welded AA2014-T6 aluminum alloy joints, 2023, 60(7): 442-460

[16] Matheron G. The intrinsic random functions and their applications. Advances in Applied Probability, 1973, 5(3): 439-468.

[17] Paik JK, Sohn JM. Effects of welding residual stresses on high tensile steel plate ultimate strength: nonlinear finite element method investigations. Journal of Offshore Mechanics and Arctic Engineering, 2012, 134(2): 021401.

[18] Pavlina EJ, Van Tyne CJ. Correlation of Yield Strength and Tensile Strength with Hardness for Steels. Journal of Materials Engineering and Performance, 2008, 17(6): 888-893.

[19] Radaj D, Sonsino CM, Fricke W. Fatigue assessment of welded joints by local approaches, 2006

[20] Rajendran C, Ben Ruben R, Ashokavarthanan P, Mallieswaran K (2022) Identifying the Effect of PWHT on Strength of Laser Beam Welding Joints of AA2024 Aluminum Alloy. ASME Open Journal of Engineering, 1. https://doi.org/10.1115/1.4053496

[21] Remes H. Strain-based approach to fatigue strength assessment of laser-welded joints, 2008

[22] Remes H, Varsta P, Romanoff J. Continuum approach to fatigue crack initiation and propagation in welded steel joints. International Journal of Fatigue, 2012, 40: 16-26.

[23] Roessle M, Fatemi A. Strain-controlled fatigue properties of steels and some simple approximations. International Journal of Fatigue, 2000, 22(6): 495-511.

[24] Saiprasertkit K, Hanji T, Miki C. Fatigue strength assessment of load-carrying cruciform joints with material mismatching in low-and high-cycle fatigue regions based on the effective notch concept. International Journal of Fatigue, 2012, 40: 120-128.

[25] Şenol M, Çam G. Investigation into microstructures and properties of AISI 430 ferritic steel butt joints fabricated by GMAW. International Journal of Pressure Vessels and Piping, 2023, 202: 104926.

[26] Serindağ HT, Çam G. Multi-pass butt welding of thick AISI 316L plates by gas tungsten arc welding: Microstructural and mechanical characterization. International Journal of Pressure Vessels and Piping, 2022, 200: 104842.

[27] Serindağ HT, Tardu C, Kirçiçek İÖ, Çam G. A study on microstructural and mechanical properties of gas tungsten arc welded thick cryogenic 9% Ni alloy steel butt joint. CIRP Journal of Manufacturing Science and Technology, 2022, 37: 1-10.

[28] Serindağ HT, Çam G. Characterizations of Microstructure and Properties of Dissimilar AISI 316L/9Ni Low-Alloy Cryogenic Steel Joints Fabricated by Gas Tungsten Arc Welding. Journal of Materials Engineering and Performance, 2023, 32(15): 7039-7049.

[29] Serindağ HT, Çam G. Microstructure and mechanical properties of gas metal arc welded AISI 430/AISI 304 dissimilar stainless steels butt joints. Journal of Physics: Conference Series, 2021, 1777(1): 012047

[30] Smith K. A stress-strain function for the fatigue of metals. Journal of materials, 1970, 5: 767-778

[31] Tsutsumi S, Fincato R, Luo P, Sano M, Umeda T, Kinoshita T, Tagawa T. Effects of weld geometry and HAZ property on low-cycle fatigue behavior of welded joint. International Journal of Fatigue, 2022, 156: 106683.

[32] Venkataramanan AR, Dhanenthiran M, Balasubramanian K, Mallieswaran K, Vinosh M. Predict the fatigue life of solution treated and aged TIG welded AA6061 aluminum alloy joints. AIP Conference Proceedings, 2022, 2527(1): 020020.

[33] Wang R, Shang D. Low-cycle fatigue life prediction of spot welds based on hardness distribution and finite element analysis. International Journal of Fatigue, 2009, 31(3): 508-514.

[34] Wang Y, Fincato R, Morita K, Wang Q, Tsutsumi S (2023) Cyclic elastoplasticity-based life assessment of fatigue crack initiation and subsequent propagation in rib-to-deck welded joints. International Journal of Fatigue 107679. https://doi.org/10.1016/j.ijfatigue.2023.107679

[35] Xu Z, Zhang J, Zhu B. Low cycle fatigue properties of a 9–12% Cr martensitic steel welded joint with Ni-based weld metal based on a local strain approach. Engineering Failure Analysis, 2022, 138: 106347.

[36] Yao Z, Omiya M, Ma N, Nishi S, Takada K, Okato K, Oide K, Kobayashi T, Han J, Terada K. Local mechanical characterization and fracture prediction modeling for resistance spot-welded joints of advanced high-strength steel. Materials Today Communications, 202336

RIGHTS & PERMISSIONS

Harbin Engineering University and Springer-Verlag GmbH Germany, part of Springer Nature