Hot Spot Stress Analysis of a Two-Planar DTY Tubular Joint Subjected to Axial Loading

Air Cooler Support Frame (ACSF) is one of the supporting structures in oil and gas field that consist of tubular and beam members. Currently, the existing common ACSF has a conventional design and could be overdesign. Therefore, the ACSF structure must be designed by considering local stress characteristics to obtain sustainable innovative design. Significant structural failure usually occurs in tubular joints because of the hot spot stress in the joint area. In this study, the ACSF structure was globally analysed to determine the critical joint which was a two-planar DTY joint, then it was locally modelled by using finite element method-based of ANSYS software for local stress analysis. The tubular joint has been modelled using solid elements including weld model and by creating fine meshing in the vicinity of the brace-chord intersection area for all braces. The axial loading is applied to investigate the local stress distribution along the brace-chord intersection line of the tubular joint for each brace. The result show that the hot spot stress of about 145 MPa for the DTY joint occurred in Brace 1 around the saddle area on the chord side under the axial tension loading.