Relaxation stability and fatigue strength of thread elements made of VT6 alloy under cyclic load

Autor: K. D. Khromushkin, O. P. Luk'yanov, O. V. Kondrat'ev, A. N. Savkin
Rok vydání: 1986
Předmět:
Zdroj: Strength of Materials. 18:32-37
ISSN: 1573-9325
0039-2316
DOI: 10.1007/bf01524222
Popis: 1. A regularity of stress relaxation has been established for the investigated alloy under cyclic load, and a link was shown between the relaxation process intensity and cyclic as well as static stress components. An analytical description is given of the relaxation process at the steady stage, and a method has been put forward for assessing the relaxation stability of the material — the arbitrary relaxation stress limit — based on the change of the relaxation process intensity as a function of stress amplitude. 2. An evaluation of the contribution to the relaxation process of various structural elements of a threaded joint was carried out. It is shown that the highest specific contribution to the relaxation stress is that supplied by the working thread. Such a joint will work at tightening stresses σm = (0.5–0.7)σ0.2 and a cyclic load at normal temperature under the conditions of stress relaxation. 3. An evaluation of the service life of a material working under conditions of cyclic stress relaxation was carried out which takes into account its fatigue and relaxation characteristics; this evaluation is based on the linear hypothesis of the summation of fatigue damage.
Databáze: OpenAIRE
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