Experimental-calculational method of evaluation of crack extension resistance of the welded joints taking the residual welded stresses fields into account

In terms of the linear mechanics of fracture the span of the stress intensity factor (SIF) is responsible for kinetics of fatigue cracks. For a developing fatigue crack, the concept of an efficient span of the SIF for a loading cycle. This concept is suitable for analytical description of fatigue cracking kinetic diagrams. Kinetic equation, describing fatigue crack propagation in high-strength low-alloyed steel welded joints with residual stress was obtained. Equation includes three constants independent of cycle stresses characteristics and residual stresses. Comparison of calculated fatigue lives and experimental results showed thair reasonable agreement.