First spinning cylinder test analysis by using local approach to fracture

In recent years, several experimental programs on large scale specimens were organized to evaluate capabilities of the fracture mechanics concepts employed structural integrity assessment of PWR pressure vessels. One test of these programs, the first spinning cylinder test, performed by Northern Research Laboratories, involved the rotation of a 200 mm thick cylinder containing a full length axial flaw to an angular speed to 2600 rpm at the temperature of 290 degrees C. A J-R curve was derived from experimental results and proved considerably larger J-values than the curve corresponding to small scale compact tension specimens tests. A geometry effect (scale, load, or size effect), was experimentally pointed out and exhibited the problem of transferability of toughness data from small scale to large scale specimens. An original analysis of this test, by means of local approach to fracture, is presented in this paper. Both compact tension specimen and spinning cylinder fracture behavior were computed by using a continuum damage mechanics model developed at EDF. Damage evolution in the structure related to cavities nucleation and growth, is directly calculated from stress and strain fields in the vicinity of the crack tip. This model enables crack initiation prediction, and also crack growth simulation. Then, combining numerical results and J-contour integral calculation provides a numerical J-R curve characteristic of the structure behavior regarding to ductile tearing