Stress Concentrations Analyses Of Tubular Joints In The Offshore Structure

The tubular joints in Offshore Platform connect different structures and deliver loads, but the stress state along the tubular joints is very complex. Due to the phenomenon of stress concentration factor, fatigue failure happens and leads the structure to failure. That is, an important parameter to evaluate the fatigue life of the structure is stress concentration factor.Several numerical models of typical tubular joints is established with SOLID elements and SHELL elements by using the finite elements software ANS YS in this paper. With this method, stress concentration factor under static load such as axial loading, in-plane bending and out-plane bending can be got. The stress distribution and stress concentration factor are compared because of the different element methods, and this can provide useful reference for the numerical simulation.One of the influences on stress concentration factor, the thickness ratio between branch and chord is also analyzed, and influence due to the change of the ratio is given in this paper. According to the result comparison between different element methods, reasonable suggestion is given when creating the finite element model about tubular joints.