Fatigue Life Assessment and Reliability Analysis of Cope-Hole Details in Steel Bridges

Authors

DOI:

https://doi.org/10.7250/bjrbe.2020-15.460

Keywords:

detection period, fatigue crack propagation life, fatigue reliability index, fracture mechanics, stress intensity factors

Abstract

Cope-hole details are widely applied to steel bridges. However, the safety of steel bridges is influenced by the fatigue performance of welded details. So, cope-hole details with flange and web subjected to axial loads were selected as the research object. Based on the basic theory of linear elastic fracture mechanics and the Finite Element Method, the stress intensity factors of cope-holes details were calculated. The influences of geometry size and crack size of the detail on the stress intensity factors were then investigated. The Paris model of fatigue crack propagation predicted the crack propagation life of cope-hole details. Besides, the fatigue limit-state equation was also established to analyse the effect of random variables (such as initial crack size, critical crack size, crack propagation parameter) on the fatigue reliability index. Finally, the recommended value of the detection period was present. The results show that the stress intensity factor gradually increases with the increase of the cope-hole radius, the weld size, the flange plate thickness, the crack length and the web thickness. However, it gradually decreases with the increase of the ratio of the long and short axle to the crack. The predicted number of fatigue cyclic loading required by the fatigue crack depth propagating from 0.5 mm to 16 mm under nominal stress amplitude of 63 MPa is 122.22 million times. The fatigue reliability index decreases with the fatigue growth parameter, the crack shape ratio and the mean of initial crack size increasing, which is relatively sensitive. However, the variation coefficient of the initial crack size has little effect on it. The detection period of cope-hole details is the service time corresponding to the fatigue accumulated cyclic loading of 198.3 million times.

References

Albuquerque, C., Silva, A. L., de Jesus, A. M., & Calçada, R. (2015). An efficient methodology for fatigue damage assessment of bridge details using modal superposition of stress intensity factors. International Journal of Fatigue, 81, 61-77. https://doi.org/10.1016/j.ijfatigue.2015.07.002

ANSYS Inc (2009). Release 12.0 documentation for ANSYS. Research Report. USA: ANSYS Incorporated.

Aygül, M., Al-Emrani, M., & Urushadze, S. (2012). Modelling and fatigue life assessment of orthotropic bridge deck details using FEM. International Journal of Fatigue, 40, 129-142. https://doi.org/10.1016/j.ijfatigue.2011.12.015

BS 7910:2013 Guide to Methfor Assessing the Acceptablity of Flaws in Metallic Structures

Cao, J. J., Yang, G. J., Packer, J. A., & Burdekin, F. M. (1998). Crack modeling in FE analysis of circular tubular joints. Engineering Fracture Mechanics, 61(5-6), 537-553. https://doi.org/10.1016/S0013-7944(98)00091-5

Choi, S. M., Tateishi, K., & Hanji, T. (2013). Fatigue strength improvement of weld joints with cope hole. International Journal of Steel Structures, 13(4), 683-690. https://doi.org/10.1007/s13296-013-4009-7

Chung, H. Y., Lin, R. S., & Lin, K. J. (2011). Evaluations of mixed-mode stress intensity factors for load-carrying fillet welded cruciform joints using the least-squares method. Journal of the Chinese Institute of Engineers, 34(2), 265-285. https://doi.org/10.1080/02533839.2011.565598

Duchaczek, A., & Mańko, Z. (2015). Determination of the value of stress intensity factor in fatigue life of steel military bridges. European Journal of Environmental and Civil Engineering, 19(8), 1015-1032. https://doi.org/10.1080/19648189.2014.992549

EN 1993-1-9 Eurocode 3. Design of Steel Structures − Part 1− 9: Fatigue

Hobbacher, A (2008). Recommendations for fatigue design of welded joints and components. IIW document IIW − 1823-07, ex XIII − 2151 r4 − 07/XV − 1254r4-07.

Ingraffea, A. R., & Manu, C. (1980). Stress‐intensity factor computation in three dimensions with quarter‐point elements. International Journal for Numerical Methods in Engineering, 15(10), 1427-1445. https://doi.org/10.1002/nme.1620151002

Jie, Z. Y. (2015). Study on the fatigue performance of welded joints in steel bridges under prior corrosion and complex stress fields (Doctoral dissertation, Dissertation, Southwest Jiaotong University (in Chinese))

Li, Y. (2008). Research on fatigue performance and reliability of highway steel bridges: (Doctoral dissertation, Dissertation, Harbin Institute of Technology, Harbin, (in Chinese))

Li, Z. (2003). An Expression of Fatigue Crack Propagation Velocity with Reliability, Journal of Xi’an Petroleum Institute (Natural Science Edition) 18(6): 67-70. (in Chinese)

Liao, P., Wei, X., Xiao, L., & Tang, J. S. (2016). Experimental study on the girder’s new detail fatigue performance of Hutong Railway Yangtze River Bridge. China Civil Engineering Journal, (8), 9. (in Chinese)

Liu, Y., & Mahadevan, S. (2009). Probabilistic fatigue life prediction using an equivalent initial flaw size distribution. International Journal of Fatigue, 31(3), 476-487. https://doi.org/10.1016/j.ijfatigue.2008.06.005

Miki, C., & Tateishi, K. (1997). Fatigue strength of cope hole details in steel bridges. International Journal of Fatigue, 19(6), 445-455. https://doi.org/10.1016/S0142-1123(97)85727-1

Nagy, W., Wang, B., Culek, B., Van Bogaert, P., & De Backer, H. (2017). Development of a fatigue experiment for the stiffener-to-deck plate connection in Orthotropic Steel Decks. International Journal of Steel Structures, 17(4), 1353-1364. https://doi.org/10.1007/s13296-017-1207-8

Wei, X., Xiao, L., & Pei, S. (2017). Fatigue assessment and stress analysis of cope-hole details in welded joints of steel truss bridge. International Journal of Fatigue, 100, 136-147. https://doi.org/10.1016/j.ijfatigue.2017.03.032

Zhang, R., & Mahadevan, S. (2001). Reliability-based reassessment of corrosion fatigue life. Structural Safety, 23(1), 77-91. https://doi.org/10.1016/S0167-4730(01)00002-9

Zhao, Z. (1995). Primary and deformation-induced high and low cycle fatigue reliability of infrastructure with updating through non-destructive inspection. (Doctoral dissertation, Dissertation, the University of Arizona, Tucson, Arizona)

Zhao, Z., Haldar, A., & Breen Jr, F. L. (1994). Fatigue-reliability evaluation of steel bridges. Journal of Structural Engineering, 120(5), 1608-1623. https://doi.org/10.1061/(ASCE)0733-9445(1994)120:5(1608)

Zhou, H., Wen, J., Wang, Z., Zhang, Y., & Du, X. (2016). Fatigue crack initiation prediction of cope hole details in orthotropic steel deck using the theory of critical distances. Fatigue & Fracture of Engineering Materials & Structures, 39(9), 1051-1066. https://doi.org/10.1111/ffe.12402

Downloads

Published

17.03.2020

How to Cite

Liao, P., Wang, Y., Zhang, X., Zhao, R., Jia, Y., & Zhu, H. (2020). Fatigue Life Assessment and Reliability Analysis of Cope-Hole Details in Steel Bridges. The Baltic Journal of Road and Bridge Engineering, 15(1), 26-46. https://doi.org/10.7250/bjrbe.2020-15.460