Revisions of fracture mechanics parameters analysis code CANIS-J(2D)

Furuhashi, Ichiro*; Wakai, Takashi 

Revisions have been done on CANIS-J(2D) that calculates fracture mechanics parameters of 2-dimensional structures containing cracks or notches. (a)Evaluation of △K between arbitrary two steps on the basis of △. (b)Evaluation of △J and △J between arbitrary two steps on the basis of △, △ε and △u. (c)Evaluation of each terms of J (△J)-integral and J (△J)-integral. (d)Execution of following three mode calculations in one job run. Mode- 0 calculation of K, J and J at any step. Mode- 1 calculation of △K, △J and △J between arbitrary two steps. Mode- 2 calculation of J and J between any continuous steps. To verify the validity of the revised code, we performed fracture mechanics analyses and crack growth simulations of thermal fatigue crack growth tests of circumferentially slitted cylinders subjected to cyclic thermal transients. And we got following results. (1)At thermal-elastic and at thermal-elasto-plastic conditions, J (△J) - integral is not path-independent and can not be properly evaluated. The reason is that J - integral is defined at elastic condition. (2)At thermal-elastic and at thermal-elasto-plastic conditions, J (△J) -integral is good enough path-independent and can be properly evaluated. The reason is that J -integral is defined at more generalized stress conditions. (3)△Jhat, thermal-elastic △K △ (or △ε) at near the crack tip, and net-section bending stress range S at crack ligament, these take approximate maximum values between the common two steps. (4)Crack growth simulations based on △J agree well with the behaviors observed at tests. (5)These results assist that, on the fracture mechanics evaluations of flawed structures subjected to complicated thermal-elasto-plastic load cycles, J (△J) -integral will be a possible fracture mechanics parameter which corresponds to ...