Leak and Break Models of Ductile Fracture of Pressurized Pipe With Axial Defects

The significance of the analytical modeling for limit load calculation of the defected pipe is outlined. The distinction between the notions of the “local” and “global” limit load is discussed. The number of simplified models for the surface axial crack, 3-D rectangular defect, through axial crack are developed which are based on the construction of the statically admissible solution. Based on them the boundary between the leak and break behavior of the pressurized pipe with the surface crack is obtained. The results of calculation are compared with experimental full-scale testing of the defected pipes.