The Significance of Plastic Zone Growth under Cyclic Loading and Crack Opening/Closing Model in Fatigue Crack Propagation

Abstract:

Fatigue cracks remain closed at lower loading level during a part of load cycle even though a tension-to-tension loading is applied. The crack closure plays a role to obstruct the generation and growth of compressive plastic zone during unloading. Cyclic plastic work, which corresponds to an irreversible energy consumed in a cracked body is generated ahead of a crack, is required as a fatigue crack driving force. The amout of cyclic plasticity is reduced by a crack closure. The crack opening/closing model based on the Dugdale model under arbitrary stress distributions for a through thickness straight crack is proposed and the fatigue crack growth under various loadings is investigated.

• Periodical: Materials Science Forum (Volume 482)
• Pages: 95-102
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.482.95
• Online since: April 2005
• Authors: Masahiro Toyosada, Koji Gotoh
• Keywords: Crack Closure, Cyclic Plasticity, Fatigue, Numerical Simulation of Fatigue Crack Growth, RPG(Re-Tensile Plastic Zone's Generated) Load, Threshold of Stress Intensity Factor

References

[1] W. Elber: The Significance of Fatigue Crack Closure, ASTM STP486, (1971), pp.230-242.

[2] M. Toyosada M. and T. Niwa: The Significance of RPG Load for Fatigue Crack Propagation and the development of a compliance measuring system. Int. J. Fracture, 67, (1994), pp.217-230.

DOI: 10.1007/bf00016261

[3] M. Toyosada, K. Yamaguchi, T. Niwa, H. Takenaka, K. Kajimoto and H. Yajima: Proposal of New Parameter for Fatigue Crack Propagation Rate based upon the Compliance Changing Phenomena and the Development of its measuring method. Journal of Society of Naval Architects of Japan 169, (1991).

DOI: 10.2534/jjasnaoe1968.1991.245

[4] M. Toyosada，M. Skorupa，T. Niwa，T. Machniewicz，K. Murakami and A. Skorupa: Evaluation of Fatigue Crack Closure from Local Compliance Measurements in Structural Steel, Fracture Mechanics Beyond 2002, Proceedings of ECF14, Cracow, Poland, (2002).

DOI: 10.1046/j.1460-2695.2002.00444.x

[5] M. Jono, A. Sugeta and Y. Uematsu: Atomic force microscopy and the mechanism of fatigue crack growth, Fatigue Fract. Engng. Mater. Struct 24, (2001), pp.831-842.

DOI: 10.1046/j.1460-2695.2001.00458.x

[6] M. Toyosada and T. Niwa: Simulation Model of Fatigue Crack Opening/Closing Phenomena for Predicting RPG Load under Arbitrary Stress Distribution Field, Proc. of the 5th Int. Offshore and Polar Eng. Conf., (1995), pp.169-176.

[7] M. Toyosada, K. Gotoh and T. Niwa: Fatigue Crack Propagation for a Through Thickness Crack: A crack propagation law considering cyclic plasticity near the crack tip, International Journal of Fatigue, Vol. 26, No. 9, (2004), pp.993-1002.

DOI: 10.1016/j.ijfatigue.2003.12.006

[8] Y. Tomita, K. Hashimoto, Y. Kariya, Y. Pan and S. Tadokoro: The effect of time history of variable amplitude loading cycles on fatigue crack growth rate, Proc. of the 2nd Int. Offshore and Polar Eng. Conf. (1992), pp.282-287.