Experimental and numerical investigation of the bending capacity of spiral-welded steel tubes

To investigate the structural behaviour of large-diameter spiral-welded steel tubes under bending, a full scale experimental program has been performed, consisting of thirteen 42-inch diameter, spiral-welded steel tubes with D/t ratios ranging between 65 and 120. Additionally, numerical studies have been conducted, using nonlinear finite element simulations. A model has been developed to simulate the performed tests, using the actual material properties and initial geometric imperfections obtained from the tested tubes. Finally, a parametric investigation has been performed that investigates the influence of initial geometric imperfections and presence of girth and coil connection welds on the bending behaviour of the considered tubes.