Fatigue crack initiation and propagation behavior from weld root of load-carrying fillet welded cruciform joints have been examined under the condition that stress range or stress intensity factor range is constant and stress ratio is kept high or low. Welding residual stresses in the joints, which are expected to have considerable influence on the fatigue crack propagation behavior, have also been measured by means of cutting method and analyzed by performing thermal conduction analyses and elasto-plastic stress analyses based on the finite element method.
