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A Study on the Effects of the Fatigue Life due to the Processing of the Butt Weld Specimens and the Fatigue Life Estimation due to the Weld Zone Profiles  

Kim Jae-Hoon (한국철도기술연구원, 철도시스템안전연구본부)
Publication Information
Journal of the Korean Society for Railway / v.9, no.4, 2006 , pp. 371-378 More about this Journal
Abstract
This study investigates the effects of the material properties and the fatigue behaviors in the SM490A material butt weld specimens due to the heat-treatment and the grinding. In the fatigue behavior, the heat-treatment affects the fatigue life. The S-N curves of both matrix specimen and butt weld specimen are reversed at some cycle by the existence or nonexistence of heat-treatment. The grinding on the bead makes the fatigue limit decrease in the all specimens. But the reinforcement removed, the fatigue limit increases at the high cycle. Also, this study investigates the fatigue life estimation by examining butt weld bead profiles. The butt weld beads, which are welded by semi-robot method, have non-uniform bead profiles described by $\theta,\;\rho$ and h. The stress concentration factors $K_t$, are changed by each different $\theta,\;\rho$ and h from 1.395 to 2.863. Hence, the sensitivity of $K_t$ is changed by each $\theta,\;\rho$ and h. As $\theta$ becomes lower and $\rho$ and h become higher, $K_t$ increases. The fatigue life can he estimated very closely for the AAY specimens without residual stress using only butt weld bead profiles. But, fur the AAN specimens with residual stress, the fatigue life must be estimated by considering both the weld bead profiles and the residual stress data.
Keywords
Fatigue life; Butt weld; Weld bead profile;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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