Influence of autofrettage on the stress intensity factors for a thick-walled cylinder with radial cracks of unequal length

1989 ◽  
Vol 39 (1-3) ◽  
pp. R29-R34 ◽  
Author(s):  
R. Arch� ◽  
M. Perl
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Intensity Factors ◽  
Radial Cracks ◽  
Walled Cylinder ◽  
Unequal Length

Stress Intensity Factors for a Radially Multicracked Partially Autofrettaged Pressurized Thick-Walled Cylinder

1988 ◽  
Vol 110 (2) ◽  
pp. 147-154 ◽  
Author(s):  
M. Perl ◽  
R. Arone´
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Favorable Effect ◽  
The Finite Element Method ◽  
Intensity Factors ◽  
Slowing Down ◽  
Wide Range ◽  
Radial Cracks ◽  
Compressive Residual Stresses ◽  
Walled Cylinder

Mode I stress intensity factors for crack arrays of up to 1024 equal radial cracks originating at the inner surface of a partially autofrettaged, pressurized thick-walled cylinder are evaluated. Both stress intensity factors i.e., KIp due to the pressurization, and the negative KIA due to the compressive residual stresses, are calculated for numerous crack arrays (n = 2–1024), a wide range of nondimensional crack lengths (1/a = 0.005–0.625), and various levels of autofrettage (ε = 30, 60, 100 percent) via the finite element method. The obtained results emphasize the notable significance of the number of cracks in the array, as well as the importance of the level of autofrettage, on the stress intensity factor prevailing at the tip of these cracks. The sensitivity of the favorable effect of the overstrain in slowing down fatigue crack growth to any decrease in the level of autofreggate is also discussed.

Weight Functions for an External Longitudinal Semi-Elliptical Surface Crack in a Thick-Walled Cylinder

1997 ◽  
Vol 119 (1) ◽  
pp. 74-82 ◽  
Author(s):  
A. Kiciak ◽  
G. Glinka ◽  
D. J. Burns
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Surface Crack ◽  
Complex Stress ◽  
Weight Functions ◽  
Stress Distributions ◽  
Intensity Factors ◽  
Reference Stress ◽  
Pressurized Cylinder ◽  
Walled Cylinder

Mode I weight functions were derived for the deepest and surface points of an external radial-longitudinal semi-elliptical surface crack in a thick-walled cylinder with the ratio of the internal radius to wall thickness, Ri/t = 1.0. Coefficients of a general weight function were found using the method of two reference stress intensity factors for two independent stress distributions, and from properties of weight functions. Stress intensity factors calculated using the weight functions were compared to the finite element data for several different stress distributions and to the boundary element method results for the Lame´ hoop stress in an internally pressurized cylinder. A comparison to the ASME Pressure Vessel Code method for deriving stress intensity factors was also made. The derived weight functions enable simple calculations of stress intensity factors for complex stress distributions.

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