Three dimensional, Mode I, Stress Intensity Factor (SIF) distributions for arrays of internal surface cracks emanating from the bore of an autofrettaged thick-walled cylinder are evaluated in this paper. The 3-D analysis is performed via the finite element (FE) method and the submodeling technique, employing singular elements along the crack front. The autofrettage residual stress field is simulated using an equivalent temperature field. More than 200 different crack configurations were analyzed. SIFs for numerous crack arrays (n = 1-180 cracks), a wide range of crack depth to wall thickness ratios (a/t=0.05-0.6), various ellipticities (a/c=0.2-1.5), and different levels of autofrettage (ε=10%-100%) were evaluated. The results clearly indicate the importance of autofrettage in reducing the effective stress intensity factor and thus, slowing the crack growth rate. The sensitivity of this favorable effect to the number of cracks in the array as well as to the level of autofrettage are also discussed.
|Number of pages||7|
|Journal||American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP|
|State||Published - 1 Dec 1998|
ASJC Scopus subject areas
- Mechanical Engineering