STRESS-ANALYSIS OF REINFORCED TUBULAR JOINTS SUBJECTED TO DIFFERENT LOAD TYPES

The reinforcing of tubular joints using doubler plates has been a comm on industrial practice as a last minute solution to resolve punching s hear problems due to axial compression. However, such reinforcements m ay have negative effects when the joints are subject to different load ing conditions. A parametric stress analysis of T reinforced welded ro und-to-round tubular joints subjected to axial tension and in-plane be nding has been performed using the finite-element technique. Sixteen s ets of geometric parameters were used for the parametric study by vary ing three parameters: doubler plate to chord thickness ratio t(p)/T; b race diameter to doubler plate length (width) ratio d/l(p); and brace to doubler plate thickness ratio t/t(p). The said study shows that t(p )/T and t/t(p) but not d/l(p) have significant effects on stress conce ntration factors in both load cases. The present results for T reinfor ced tubular joints are compared with those for the corresponding unrei nforced joints obtained by the Authors and other researchers. In gener al, the reinforced joints are as good as the corresponding unreinforce d joints in withstanding axial tension and in-plane bending, provided that certain criteria for the selection of doubler plates are adopted. Although out-of-plane bending is not considered in the present study, the influence of various geometric parameters are expected to show tr ends similar to those observed for axial tension and inplane bending.