FEM Analysis of the Welding Seams Geometry in Case of Fillet Welds

Abstract

The role of the welding seam is to achieve the non-removable joint between two or more parts. In principle, three geometric profiles of the welding seams can be obtained: straight profile; concave profile and convex profile. In practice, this geometric shape of the weld seam profile is very important, both in terms of the resistance of the joint to static stresses and in terms of its fatigue life. There are many factors that can influence the geometric shape of the weld seam: the welding process; welding regime; the nature of the filler materials used, the rehabilitation techniques applied and others. Often, this geometric shape of the weld bead is neglected, which is particularly dangerous due to the fact that an improper geometric shape can generate low mechanical strength in static loads or poor fatigue strength in variable loads. An optimum of the geometric configuration of the welding must be found, which reconciles both situations: the mechanical resistance in case of static stresses and also the fatigue resistance in case of variable loads. In this paper, an analysis will be made with finite elements for the straight and convex profile of the welding seams in the case of fillet welds subjected to fatigue. Several elements will be considered such as: damage; total deformation; fatigue sensitivity versus loading history; equivalent von Misses stress; safety factor.