The process of forming or fabricating of a part or a structure often becomes the most critical factor in production, particularly when fatigue loading is present. When the welding is used as a fabrication process, the welded elements become the “weakest” regions of the structural element and, as a result, extra material is usually added to these regions on design stage, to prevent premature failure. For example, even in the case of butt welded joint ground flush to plate, the design stress range is still lower by 22-38% than the same parameter for the base material.
A number of engineering tools were developed to resolve the above-mentioned problem. For example, the application of Ultrasonic Peening (UP) may increase (“restore”) the design stress range of welded elements, in some cases up to the fatigue strength of the base material. A software was developed for analysis of the influence of residual stresses on the fatigue life of welded elements and for Optimum Application of UP process. The developed Engineering Tools could be effectively applied on the stages of design, manufacturing and repair of parts and welded elements