Low cycle fatigue crack growth and ductile fracture under dynamic/cyclic loadings for Japanese carbon steel piping: Part II--Analytical study

Dynamic fracture behavior of circumferentially cracked pipe is important to evaluate the structural integrity of nuclear piping from the view point of leak-before-break concept under seismic conditions. Fracture tests were conducted for Japanese carbon steel (STS42) pipes which were subjected to cyclic or dynamic monotonic loading. This paper describes the analytical studies for these pipe tests. J-integral approach was applied to evaluate the cyclic crack growth. A new equation for calculating ΔJ for a circumferentially throughwall cracked pipe subjected to bending was proposed. The effects of dynamic or cyclic loading on pipe fracture were also investigated