Effect of Fillet Welds on Initial Rotational Stiffness of Welded Tubular Joints

Welded tubular joints are widely used in optimization of tubular structures. The most important parameter in optimization of these joints is their initial rotational stiffness. For today there is no any available analytical method that allows calculating rotational stiffness for joints with an angle different from 90 degrees. Conducting computationally intensive finite element analyses (FEA) usually renders the optimization procedure inapplicable. Constructing an approximate surrogate model of the joint responses can lead to a significant reduction of computational efforts. However most of surrogate models are constructed for joints with only butt welds. This article proposes a simple method for implementing fillet welds in surrogate modeling of tubular joints. Using this method the effect of fillet welds on initial rotational stiffness of joints is analyzed.