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Furuhashi, Ichiro*; Wakai, Takashi
PNC TN9410 95-080, 84 Pages, 1995/02
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 △, △
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 △) 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 ...
Furuhashi, Ichiro*; *
PNC TN9410 94-201, 301 Pages, 1994/04
Development and revisions of simplified crack analysis code CANIS-system were done for fracture mechanics evaluation of FBR structures. CANIS-system is composed of CANIS-G, K and -I. Following revisions were done on CANIS-G that evaluate creep fatigue crack growth history. (1.1)0uter crack of cylinder can be treated, addition to inner crack. (1.2)Axial bending load on cylinder can be treated. (1.3)Displacement controlled load such as thermal stresses can be easily treated. (1.4)Libraly of shape functions for net section stress and libraly of stress intensity factor solutions were expanded to support above subjects. (1.5)Material properties such as elasto-plastic stress-strain relation, creep strain relation, creep rupture time and fatigue failure life of 7 kinds of materials those have been gotten in PNC were added on libralies. (1.6)Backward analysis can be done to estimate past time crack shapes. And now CANIS-K that evaluate fracture mechanics parameters and CANIS-I that evaluate crack initiation probability have been developped. CANIS-K can be used in the following subjects. (2.1)Calculate and print details of fracture mechanics parameters such as stress intensity factor K, J-integral and creep J-integral for given crack shapes, and maximum and minimum values and time histories of those parameters. (2.2)Calculate and print crack growth rates, crack opening area and leak rates. CANIS-I can be used in the following subjects. (3.1)Evaluate time dependant fatigue damage and creep damage. (3.2)Evaluate time dependant crack initiation probability with reference of statistical crack initiation data that caused by fatigue damage or by creep damage. Input data format and subroutine programs of these CANIS-G, -K and -I are commonly, so future expansions and revisions will be done easily and commonly. CANIS is very powerful computational tool in the following regions and can be employed in many practical applications. (4.1)Remaining life predictions of cracked ...
