The Fatigue Fracture Criterion Based on the Latent Energy Approach

Abstract

The extensive literature on the fatigue problem, published for more than one hundred years, is reviewed by the known scientists [1,2]. As it follows from these investigations, the fundamental amount of failures in engineering practice connected with the fatigue fractures of materials and structure elements. The fatigue problem is complicated one and it is not solved yet. So the theoretical and experimental investigations of this problem will be continued. In our paper the energy approach to formulate the fatigue strength criterion is proposed. The criterion is based on the conception of the latent energy [3-7]. This conception was not applied previously to the fatigue problem. The latent energy is consumed to generate the irreversible deformation and to damage and fracture of metallic materials. So the fatigue fracture criterion can be formulated using the results of latent energy measurements in the macro experiments. This is most impotent advantage of the proposed approach. The logistic function is used to describe the dependence of latent energy from the value of irreversible deformation. It is assumed that the cyclic strength of metals is defined by the latent energy, stored in specimen, when it is reached the critical value in accordance with the logistic curve in a saturation zone. This proposal is used to formulate the fatigue strength criterion. The functions and parameters of received criterion are concretized and comparisons with experimental results for axial cyclic tension for sheet aluminum alloy specimens are given.

The extensive literature on the fatigue problem, published for more than one hundred years, is reviewed by the known scientists [1,2]. As it follows from these investigations, the fundamental amount of failures in engineering practice connected with the fatigue fractures of materials and structure elements. The fatigue problem is complicated one and it is not solved yet. So the theoretical and experimental investigations of this problem will be continued. In our paper the energy approach to formulate the fatigue strength criterion is proposed. The criterion is based on the conception of the latent energy [3-7]. This conception was not applied previously to the fatigue problem. The latent energy is consumed to generate the irreversible deformation and to damage and fracture of metallic materials. So the fatigue fracture criterion can be formulated using the results of latent energy measurements in the macro experiments. This is most impotent advantage of the proposed approach. The logistic function is used to describe the dependence of latent energy from the value of irreversible deformation. It is assumed that the cyclic strength of metals is defined by the latent energy, stored in specimen, when it is reached the critical value in accordance with the logistic curve in a saturation zone. This proposal is used to formulate the fatigue strength criterion. The functions and parameters of received criterion are concretized and comparisons with experimental results for axial cyclic tension for sheet aluminum alloy specimens are given.

Keywords

Fatigue Fracture Criterion, Energy Approach, Latent Energy, Heat Energy, Logistics Function, Damage Parameter

Fatigue Fracture Criterion, Energy Approach, Latent Energy, Heat Energy, Logistics Function, Damage Parameter

Cite this paper

A. Arutyunyan and R. Arutyunyan, "The Fatigue Fracture Criterion Based on the Latent Energy Approach,"*Engineering*, Vol. 2 No. 5, 2010, pp. 318-321. doi: 10.4236/eng.2010.25041.

A. Arutyunyan and R. Arutyunyan, "The Fatigue Fracture Criterion Based on the Latent Energy Approach,"

References

[1] S. S. Manson, “Fatigue: A Complex Subject－Some Simple Approximations,” Experience Mechanics, Vol. 7, 1965, pp. 193-225.

[2]
J. Schijve, “Fatigue of Structures and Materials in the 20th Century and the State of the Art,” International Journal of Fatigue, Vol. 25, 2003, pp. 679-702.

[3]
G. I. Taylor and W.S. Farren, “The Heat Developed during Plastic Extension of Metals,” Proceedings of the Royal Society A, London, Vol. 107, 1925, pp. 422-451.

[4]
G. I. Taylor and H. Qunnney, “The Latent Energy Remaining in a Metal after Cold Working,” Proceedings of the Royal Society A, London, Vol. 143, 1934, pp. 307-326.

[5]
M. A. Bolshanina and V. E. Panin, “The Latent Energy of Deformation,” Issledovanie po fizike tverdogo tela, Academy of Science of USSR, Moscow, 1957, pp. 193-234.

[6]
O. W. Dillon, “The Heat Generated during Torsional Oscillations of Copper Tubes,” International Journal of Solids and Structures, Vol. 2, 1966, pp. 181-204.

[7]
M. B. Bever, D. L. Holt and A. L. Titchener, “The Stored Energy of Cold Work,” Progress in Materials Science, Vol. 17, 1973, pp. 5-177.

[8]
W. Oliferuk, M. Maj and B. Raniecki, “Experimental Analysis of Energy Storage Rate Components during Tensile Deformation of Polycrystals,” Materials Science and Engineering A, Vol. 374, 2004, pp. 77-81.

[9]
O. Plechov, N. Saintier and O. Naimark, “Experimental Investigation of the Processes of Energy Storage and Dissipation in Iron during the Elastic Plastic Deformation,” Journal of Technical Physics, Vol. 9, 2007, pp. 135-137.

[10]
P. Rosakis, A. J. Rosakis, G. Ravichandran and J. Hodowany, “A Thermodynamic Internal Variable Model for the Partition of Plastic Work into Heat and Stored Energy in Metals,” Journal of the Mechanics and Physics of Solids, Vol. 48, 2000, pp. 581-607.

[11]
A. R. Arutyunyan, B. A. Zimin, Y. V. Sud’enkov, “The Application of Optics-Spectroscopy Method to Investigate Fatigue of Construction Materials,” Proceedings of International Conference on Topical Problems of Continuum Mechanics, Erevan, 2007, pp. 63-68.

[12]
V. I. Arnold, “Ordinary Differential Equations,” Nauka, Moscow, 1971.

[13]
R. A. Arutyunyan, “The Problem of Deformation Aging and Prolonged Fracture in Material Science,” S.-Petersburg University Press, Sankt-Petersburg, 2004.

[14]
A. N. Orlov, “The Long-Time Strength and Physics of Fracture,” Trudy TsKTI, Vol. 230, 1986, pp. 42-46.

[15]
P. G. Forrest, “Fatigue of Metals,” Mashinostroenie, Moscow, 1968.

[16]
V. T. Troschenko, “Fatigue and Nonelasticityof Metals,” Naukova Dumka, Kiev, 1971.

[17]
O. Plechov, O. Naimark, R. Valiev, I. Semenova, N. Saintier and T. Palin-Luc, “Experimental Investigation of Anomalous Energy Absorption in Nanocrystal Titan Under the Cyclic Loading,” Letters in Journal of Technical physics, Vol. 34, No. 13, 2008, pp. 33-40.