| 2007 №07 (05) | 2007 №07 (07) |
The Paton Welding Journal, 2007, #7, 23-25 pages
Extension of the life of metal span structures of railway bridges with fatigue damage
V.I. Kirian, V.V. Knysh, A.Z. Kuzmenko
E.O. Paton Electric Welding Institute of the NASU. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.Abstract
Considered are the features of early accumulation of fatigue damage, initiation and development of fatigue cracks in welded components of metal span structures of railway bridges. A high effectiveness of application of high-frequency mechanical peening (HFMP) for extension of residual life of welded joints after accumulation of considerable damage in them, including development of cracks up to 1 mm deep, was established. Methods of retardation have been studied for propagating cracks, and the most efficient of them have been determined, namely inducing compressive residual stresses in the fatigue crack propagation path by applying local heating of the metal; placing a high-strength bolt in the drilled-out hole near the crack tip; repair of the metal zone damaged by the fatigue crack using welding with HFMP.
Keywords: metal span structures, railway bridges, fatigue cracks, welded joint, high-frequency mechanical peening, extension of fatigue life
References
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