Validation of the state-space model of fatigue crack growth in ductile alloys under variable-amplitude load via comparison of the crack-opening stress data. (English) Zbl 1196.74250

Summary: This paper presents improvements to the state-space model, through enhancements in the calculations of the constraint factor. These improvements are similar to the calculation procedure of the constraint factor in FASTRAN-II model, which has been extensively validated. The model predictions are compared to various crack growth data as well as FASTRAN-II predictions. Heather to, the state-space model has only been validated through the crack-length data but this paper presents the validation of the state-space model via comparison of the experimental crack-opening stress and crack-length data, thus involving both the states of the state-space model in experimental validation of the model. The experimental data are also compared to the crack-opening stress in FASTRAN-II predictions. Simulation results validate the modeling method of treating the crack-opening stress as a state variable or internal variable. The state-space model considerably reduces the computational complexity of the fatigue crack growth model under variable-amplitude load.


74R20 Anelastic fracture and damage


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[5] Newman, J.C. Jr. (1984). A crack-opening stress equation for fatigue crack growth. International Journal of Fracture 24, R131?R135.
[6] Newman, J.C. Jr. (1992). FASTRAN-II ? A Fatigue Crack Growth Structural Analysis Program. NASA Technical Memorandum 104159, Langley Research Center.
[7] Elber, W. (1970). Engineering Fracture Mechanics.
[9] Harter, J.A. AFGROW Users? guide and technical manual. Report No. AFRL-VA-WP-1999-3016, Air Force Research Laboratory.
[10] Schijve, J. and Jacobs, F.A. Tromp, P.J. (1971). The effect of load sequence under fatigue crack propagation under random loading and program loading. NLR TR 71014 U, National Aerospace Laboratory NLR, The Netherlands.
[15] McMillan, J.C. and Pelloux, R.M.N. (1967). Fatigue crack propagation under program and random loads. Fatigue Crack Propagation, ASTM STP 415, 505-532 (Also BSRL Document D1-82?0558 1966).
[16] McMaster, F.J. and Smith, D.J. (1999). Effect of load excursions and specimen thickness on crack-closure measurement. Advances in Fatigue Crack-closure Measurements and Analysis, ASTM STP 1343, West Conshohocken, 246–264.
[17] Kailath, T. (1980). Linear Systems, Prentice-Hall Englewood Cliffs. · Zbl 0454.93001
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