Fatigue life analysis of steel tube member with T-shaped welded joint by FEM

초록

T-shaped welded steel pipe members are one of the pipe members which are widely used for civil and architecture structures. T-shaped tube member is connected by welding. These pipe members are known that fatigue crack in welding joint is frequently occurred due to fatigue loading. In this paper, the 3D FEM fatigue analysis method was proposed. In order to simulate a fatigue phenomenon that can predict fatigue life, 3D FEM analysis method considered the following theories: cyclic hysteresis constitutive equation, isotropic hardening rule, kinematic hardening rule, ratcheting effect, strain range effect, mean stress relaxation effect and cyclic elastic-plastic-damage constitutive equation etc. In order to simulate welded pipe member, threedimensional non-steady heat conduction analysis and thermal elastic-plastic analysis were also carried out. The overall fatigue behavior of steel pipe member was clarified under high cycle loading. From the result of this study, it was analyzed the fatigue life of the T-type pipe welding member under high cycle loading by FEM. And, it was clarified that the proposed 3D Fatigue FEM analysis method is useful as a numerical tool for calculating the remaining fatigue life accompanied with crack.

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