CONTACT BETWEEN VESSEL SHELL AND WELDED PAD IN NOZZLE REINFORCEMENT

In the thin shell analysis of welded pad reinforced nozzles in pressur e vessels, no contact between pad and vessel is often assumed. The sig nificance of this contact force to the stress distribution in the stru cture is little known. In this paper, stress results from the finite e lement analysis, which includes the contact force between the pad and the vessel, are reported. A comparison of the finite element results w ith those from thin shell analysis and experiments shows that the fini te element method with contact assumption yields improved theoretical prediction for the stress distribution. The effect of both the gap and friction between the pad and the vessel are also investigated.