Abstract:

Paper analyzes the expression of stress intensity factor of thick-walled cylinder with cracks, and points out t Newman-Raju s solution of free-surface influence coefficients is the optimum expression of calculating the of fatique crack propagation of thick-walled cylinder. At the same time, this paper indicates that the life of que crack propagation can be greatly increased by autofrettage, and the longest life will be got when the ipment is autofrettaged by 100 % over strain degree.

Key words: Fatique crack propagation, Stress intensity factor, Residual stress