Most welded structures contain residual welding stresses after their final processing. These stresses may reach the yield point of the material at room temperature. Further, under certain conditions (the presence of crack-type defects, embrittled zones of metal, etc. ), residual welding stresses may reduce the brittle strength (technical cohesive strength) and endurance of elements of the structures. The character of the distribution of these stresses depends on many factors (e. g., on the geometry of the weld, mode of welding, and subsequent heat treatment, the properties and structure of the metal, etc. ). Using certain assumptions, the present work examines the strength and endurance of a weld loaded by the following variants: External loads absent (residual stresses acting alone); residual stresses acting in combination with external static and alternating loads. It should be noted that LU the first and second loading variants, we can discuss only the strength of the weld, not its endurance. 1, Basic Assumptions, Definition of Problem, and Determination of Stress Intensity Factor. Let. 1) the residual stress curve be symmetrical relative to the weld, with the stresses being distributed sinusoidally with respect to magnitude along the direction perpendicular to the weld {Fig. 1).