Experimental and numerical analysis of a novel tubular joint for transmission tower

Abstract A novel type of tubular X-joint is evaluated in this study which combines both flange connection and welded connection for practical steel tube transmission tower. Full-scale experiments are carried out to investigate the monotonic behavior of the joints under both axial tensile and compressive load. The failure modes, load-displacement curves, load-strain curves, deformation development and ultimate strength are studied and discussed. Non-linear finite element analysis of the proposed tubular X-joint not only captures the discernible behavior observed during the tests to verify the experimental results, but also help study stress distribution that cannot be directly measured during the tests. Both experimental and numerical results show that the novel type of joints have adequate bearing capacity with good safety margin and the weak parts are mainly concentrated on the vicinity of intersection regions. Finally, several different design codes are used to calculate the ultimate strength of the proposed joints under investigation. The difference between experimental results and current design methods can be attributed to the fact that the connection adopted in the joints is different from the conventional welded tubular X-joint in codes.