Fatigue Damage Accumulation of Welded Bridge Member during Crack Growth Propagation with Initial Crack

Abstract:

The crack growth behavior and the fatigue life of welded members with initial crack in bridges under traffic loading were investigated. Based on existed fatigue experiment results of welded members with initial crack and the fatigue experiment result of welded bridge member under constant stress cycle, the crack keeps semi-elliptical shape with variable ratio of a/c during crack propagation. The calculated method of the stress intensity factor necessary for welded bridge member crack propagation was discussed. The crack remained semi-elliptical shape with variable ratio of a/c during crack propagation. The fatigue crack propagation law suitable for welded steel bridge member fatigue crack propagation analysis was deduced based on the continuum damage mechanics and fracture mechanics. The proposed fatigue crack growth model was then applied to calculate the crack growth and the fatigue life of existed welded member with fatigue experimental result. The calculated and measured fatigue life was generally in good agreement, at suitable initial conditions of cracking, for welded member widely used in steel bridges.

• Periodical: Key Engineering Materials (Volumes 353-358)
• Pages: 24-27
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.353-358.24
• Online since: September 2007
• Authors: Tai Quan Zhou, Tommy Hung Tin Chan
• Keywords: Crack Growth, Fatigue Damage, Fatigue Life, Initial Crack, Welded Bridge Members

References

[1] BS 7910. Guide on Methods for Assessing the Acceptability of Flaws in Fusion Welded Structures. (BSI, London, 2000).

[2] NCHRP (National Cooperative Highway Research Program) Report 354: Resistance of Welded Details under Variable Amplitude Long-life Fatigue Loading (National Academy Press, USA 1993).

[3] J.W. Fisher: Fatigue and Fracture in Steel Bridges: Case Study (John Wiley Sons, USA 1984).

[4] X.B. Lin, R.A. Smith: Engineering Fracture Mechanics Vol. 63, (1999), P. 523.

[5] T.Q. Zhou: (Ph.D. Dissertation, Southeast University, Nanjing, China, 2003), P. 68.

[6] Z.X. Li, T.H.T. Chan: Theoretical and Applied Fracture Mechanics, Vol. 35, (2001), P. 81.

[7] J.C. Newman, I.S. Raju: Engineering Fracture Mechanics, Vol. 15, (1981), P. 185.

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