Numerical stress analysis of tubular joints

The finite element analysis (FEA) presented in this paper pertains to the stress analysis of both the welded tubular T and X joints and is aimed to assess both the importance of the presence of the weld geometry and the suitability of shell and solid elements with regards to the FEA of welded tubular joints and, additionally, to confirm or dispute a correlation between the standards AWS D1.1 and DNVGL-RP-C203 with regards to the minimum size of the weld geometry. Using symmetry, three unit-load cases are investigated: axial loading, in-plane and out-of-plane bending. The results indicate that the FE models acknowledging the presence of the weld geometry and using solid elements are more suitable for the FEA of welded tubular joints and, moreover, the stress concentration factor (SCF) obtained at the chord “crown” location from the FE models subjected to the axial load case either approach, as in the case of the welded tubular T joint, or surpass, as in the case of the welded tubular X joint, the value estimated from the parametric equations as given in DNVGL-RP-C203.