The effect of compression stresses, stress level and stress order on fatigue crack growth of multiple site damage
Tóm tắt
Structural components are generally subjected to a wide stress spectrum over their lifetime. Service loads are accentuated at the areas of stress concentration, mainly at the connection of components. When there is a critical level of multiple site damage at connections, cracks link up to form a large crack which abruptly reduces the residual strength of the damaged structural member. Therefore, it is important to estimate the fatigue life before the cracks link up due to critical multiple site damage. In this study, the extended finite element method was applied to predict lifetime under constant amplitude cyclic loadings of fatigue tests on several multiple site damage specimens made of Al 2024‐T3. Then the multiple crack growths under service stress spectra are calculated to investigate the effects of compressive stress, stress orders and the effect of sequence cyclic loadings on stress levels by using Forman and NASGROW equations.
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Tài liệu tham khảo
Murthy A. R. C., 2004, State‐of‐the‐art review on fatigue crack growth analysis under variable amplitude loading, J. Inst. Eng. (India) Civil. Eng. Div., 85, 118
Abdullah S., 2009, Fatigue crack growth modelling of aluminium alloy under constant and variable amplitude loadings, Struct. Durability Health Monit., 5, 109
Yu M. Topper T. H.andAu P.(1984)The effect of stress ratio compressive load and underload on the threshold behaviour of a 2024‐T351 aluminium alloy. In:Proceedings of the Fatigue 84 Second International Conference on Fatigue and Fatigue Threshold Birmingham UK 179–190.
Tack A.andBeevers C. J.(1990)The influence of compressive loading on fatigue crack propagation in three aerospace bearing steels. In:Proceedings of the Fourth International Conference on Fatigue and Fatigue Threshold UK MPCE Ltd Honolulu 1179–1184.
Elber W., 1971, The significance of fatigue crack closure, ASTM STP, 486, 230
Iwasaki T., 1982, Fatigue crack growth under random loading, Naval. Arch. Ocean. Eng.(Jpn)., 20, 194
Ohrloff N., 1988, Fatigue Crack Propagation Behaviour Under Variable Amplitude Loading
Schijve J., 1988, Fatigue crack closure observations and technical significance, ASTM STP, 982, 5
AFGROW, 2003, AFGROW Reference Manual (version 4.0)
NASGRO, 2002, NASGRO Reference Manual (version 4.02)
Newman J. J., 1981, A crack closure model for predicting fatigue crack growth under aircraft spectrum loading, ASTM STP, 748, 53
Newman J. J., 1992, FASTRAN II—A Fatigue Crack Growth Structural Analysis Program
de Koning A. U., 1988, Analysis of crack opening behavior by application of a discretized strip yield model, ASTM STP, 982, 437
Joseph W. C., 2006, Fatigue Crack Growth equation
Walker E. K., 1970, The Effect of Stress Ration During Crack Propagation and Fatigue for 2024‐T3 and 7076‐T6 Aluminium
Willenborg J. Engle R. M.andWood H. A.(1971)A crack growth retardation model using an effective stress concept.Air force flight dynamics lab Wright‐Patterson AFB OH.
Kassim SA‐R, 2008, Statical modeling of fatigue crack growth rate in ore‐strained 7475‐T7351 aluminium alloy, Mater. Sci. Eng., 486, 585, 10.1016/j.msea.2007.10.083
nCode(2003)User Guide Manual. ICE‐FLOW Cracks Growth V2.0.
Newman J. C., 1984, A crack opening stress equation for fatigue crack growth, Int. J. Fract., 24, R131, 10.1007/BF00020751
Abdullah S., 2011, Effects of load sequence on fatigue crack growth in pressure vessels, AMR., 160, 1217
Beretta S.andVilla A. A. R. V.(2010)approach for the analysis of fatigue crack growth with NASGRO equation. In:Proceedings of the ASRANet2010 Conference Edinburgh Scotland .
Forsyth P. J. E., 1961, Proceedings of the Crack Propagation Symposium, 76
Thanh C. D., 2011, Predictions of fatigue crack growth and residual strength in plane and shell structures using numerical methods without remeshing
Marco A. M.andJaime T. P. de C.(2001)Propagation of 2D fatigue cracks under complex loading. In:Proceedings of the 56o Congresso Anual da ABM – 16 a 19 de julho de Belo Horizonte MG .
Broek D., 1988, The Practical use of Fracture Mechanics
Meggiolaro M.andCastro J. T. P.(2001)Comparison of load interaction models in fatigue crack propagation. In:Proceedings of the XVI Brazilian Congress in Mechanical Engineering (COBEM) ABCM Uberlândia Minas Gerais Brazil 247–256.
MIL‐STD‐1530A(1975) Aircraft Structural Integrity Program Airplane Requirements.
Nelson D. V., 1977, Predictions of Cumulative Fatigue Damage using Condensed Load Histories
Adam N., 2003, Rain flow counting method