The Paton Welding Journal, 2004, №03

2004 №03 (04)

2004 №03 (06)

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The Paton Welding Journal, 2004, #3, 26-29 pages

Allowance for effect of cycle asymmetry on crack resistance of steels and welded joints at two-frequency loading

V.S. Kovalchuk

E.O. Paton Electric Welding Institute of the NASU 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.

Abstract
It was established that increase in a coefficient of cycle asymmetry from R = 0 up to R = 0.5 at two-frequency loading leads to 3-4 times increase in propagation rate of fatigue cracks in parent metal and up to 2 times increase in weld metal of butt welded joints of high strength (sy ~ 1000 MPa) steel. Calculation method is offered allowing determination of a cyclic crack resistance of structural materials and welded joints under the conditions of a two-frequency loading using the fatigue fracture diagrams corresponding to a single-frequency loading with an appropriate coefficient of a cycle asymmetry.
Keywords: cyclic crack resistance, two-frequency loading, cycle asymmetry, steels, welded joints, calculation

References

1. Forman, R., Kerni, V., Angle, R. (1967) Computational investigations of crack propagation in cyclic-loaded structures. Transact, of ASME, Series I), 3, 8−16.
2. Trufvakov, V.I., Knysh, V.V., Mikheev, P.P. et al. (1987) Relationship between fatigue crack propagation rate and cy¬cle asymmetry. Avtomatich. Svarka, 3, 5−7.
3. Kovalchuk, V.S. (2003) Allowance for effect of cycle asymmetry on cyclic crack resistance of materials and welded joints. The Paton Welding J., 9, 2−4.
4. Trufyakov, V.I., Kovalchuk, V.S. (1982) Determination of service life at two-frequency load. Part 2. Proposed proce¬dure. Problemy Prochnosti, 10, 15−20.
5. Troshchenko, V.T., Sosnovsky, L.A. (1987) Fatigue resistance of metals and alloys. Refer. Book. Part 1. Kiev: Naukova Dumka

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Suggested Citation

V.S. Kovalchuk (2004) Allowance for effect of cycle asymmetry on crack resistance of steels and welded joints at two-frequency loading. The Paton Welding J., 03, 26-29.

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