용접 비드 형상을 이용한 용접 시편의 피로수명 예측 연구

초록

This study investigates the fatigue life estimation of butt weld specimen for the railway vehicle by examining butt weld bead profiles. The butt weld beads, which are welded by semi-robot method, have non-uniform bead profiles described by θ, ρ and h. The stress concentration factors, Kt, are changed by different θ, ρ and h form 1.395 to 2.863. Hence, the sensitivity of Kt is changed by each θ, ρ and h. As θ becomes lower and ρ and h become higher, Kt increases. The fatigue life can be estimated very closely for the AAY specimens without residual stress using only butt weld bead profiles. But, for the AAN specimens with residual stress, the fatigue life must be estimated by considering both the weld bead profiles and the residual stress data.

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