On the Prediction of Stress Intensity Factors for Axisymmetric Cracks in Thin-Walled Cylinders From Plane Strain Solutions

1985 ◽  
Vol 107 (3) ◽  
pp. 227-231 ◽  
Author(s):  
Weili Cheng ◽  
Iain Finnie
Keyword(s):  
Stress Intensity ◽  
Stress Distribution ◽  
Plane Strain ◽  
Numerical Solutions ◽  
Axial Stress ◽  
Stress Fields ◽  
Intensity Factors ◽  
Thin Walled ◽  
Axial Stress Distribution ◽  
Axisymmetric Cracks

It is shown that stress intensity solutions for axisymmetric cracks in thin-walled cylinders may be obtained for any prescribed axial stress distribution from plane strain solutions. This approach is illustrated by comparing solutions for internal circumferential cracks in several axial stress fields with numerical solutions for axisymmetric cracks. It may also be applied to external axisymmetric cracks.

Stress Intensity Factors due to Residual Stresses in Thin-Walled Girth-Welded Pipes

1981 ◽  
Vol 103 (1) ◽  
pp. 66-75 ◽  
Author(s):  
E. F. Rybicki ◽  
R. B. Stonesifer ◽  
R. J. Olson
Keyword(s):  
Residual Stress ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Stress Distribution ◽  
Intensity Factor ◽  
Crack Growth ◽  
Residual Stress Distribution ◽  
Intensity Factors ◽  
Thin Walled Pipe ◽  
Thin Walled

The effect of a girth-weld-induced residual stress field on the linear elastic fracture mechanics of a thin-walled pipe is examined. The procedure for using the residual stress distribution to compute KI and KII for a circumferential crack which is growing radially is described. In addition to the two-pass girth weld, stress intensity factors are computed for a residual stress distribution in a flat plate and for a hypothetical residual stress state in a second thin-walled pipe. The computed stress intensity factor for the flat plate geometry and its residual stress distribution are compared with a solution from the literature as a check on the computational procedure. The through-the-thickness residual stress distribution due to the two-pass girth weld is similar to a half-cosine wave. For purposes of comparison, the hypothetical through-the-thickness distribution selected for the second pipe is similar to a full cosine wave. The stress intensity factor is presented as a function of crack depth for a crack initiating on the inner surface of the pipe. The redistribution of residual stresses due to crack growth is also shown for selected crack lengths. The study shows that residual stress-induced crack growth in pipes can be significantly different from that in flat plates due to the possibility of locked-in residual bending moments in the pipe. These locked-in moments can have effects similar to externally applied loads and can either promote or restrain crack growth. A residual stress distribution is illustrated in which crack growth, if initiated, would continue through the entire wall. Also, a residual stress distribution is illustrated for which the crack could arrest after a certain amount of growth.

Determination of Stress Intensity Factors for Partial Penetration Axial Cracks in Thin-Walled Cylinders

1986 ◽  
Vol 108 (2) ◽  
pp. 83-86 ◽  
Author(s):  
Weili Cheng ◽  
Iain Finnie
Keyword(s):  
Stress Intensity ◽  
Hoop Stress ◽  
Numerical Solutions ◽  
Stress Distributions ◽  
Intensity Factors ◽  
Axial Crack ◽  
Thin Walled ◽  
Walled Cylinder ◽  
Good Agreement

An approach based on the use of rotation and displacement solutions for a cracked element in plane strain is used to obtain the stress intensity factor for a long axial crack in a thin-walled cylinder. The hoop stress distribution in the cylinder prior to introduction of the crack is arbitrary. Results obtained with this approach are in good agreement with numerical solutions for several hoop stress distributions.

scholarly journals Experimental Investigation of Steel Plate Shear Walls under Shear-Compression Interaction

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yang Lv ◽  
Ling Li ◽  
Di Wu ◽  
Bo Zhong ◽  
Yu Chen ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Steel Plate ◽  
Axial Stress ◽  
Shear Walls ◽  
Shear Capacity ◽  
Steel Plate Shear Walls ◽  
Steel Plate Shear Wall ◽  
Gravity Load ◽  
Moment Resisting ◽  
Axial Stress Distribution

Four scaled one-storey single-bay steel plate shear wall (SPSW) specimens with unstiffened panels were tested to determine their behaviour under cyclic loadings. The shear walls had moment-resisting beam-to-column connections. Four different vertical loads, i.e., 300 kN, 600 kN, 900 kN, and 1200 kN, representing the gravity load of the upper storeys were applied at the top of the boundary columns through a force distribution beam. A horizontal cyclic load was then applied at the top of the specimens. The specimen behaviour, envelope curves, axial stress distribution of the infill steel plate, and shear capacity were analyzed. The axial stress distribution and envelope curves were compared with the values predicted using an analytical model available in the literature.

Determination of Stress Intensity Factors for Gradient Stress Fields

1977 ◽  
Vol 99 (3) ◽  
pp. 477-484 ◽  
Author(s):  
J. M. Bloom ◽  
W. A. Van Der Sluys
Keyword(s):  
Stress Intensity ◽  
Crack Length ◽  
Stress Intensity Factors ◽  
Maximum Stress ◽  
Nuclear Industry ◽  
Stress Fields ◽  
Polynomial Method ◽  
Intensity Factors ◽  
Asme Code ◽  
Linear Envelope

This paper evaluates eight different analytical procedures used in determining elastic stress intensity factors for gradient or nonlinear stress fields. From a fracture viewpoint, the main interest in this problem comes from the nuclear industry where the safety of the nuclear system is of concern. A fracture mechanics analysis is then required to demonstrate the vessel integrity under these postulated accident conditions. The geometry chosen for his study is that of a 10-in. thick flawed plate with nonuniform stress distribution through the thickness. Two loading conditions are evaluated, both nonlinear and both defined by polynomials. The assumed cracks are infinitely long surface defects. Eight methods are used to find the stress intensity factor: 1–maximum stress, 2–linear envelope, 3–linearization over the crack length from ASME Code, Section XI, 4–equivalent linear moment from ASME Code, Section III, Appendix G for thermal loadings, 5–integration method from WRC 175, Appendix 4 for thermal loadings, 6–8-node singularity (quarter-point) isoparametric element in conjunction with the displacement method, 7–polynomial method, and 8–semi-infinite edge crack linear distribution over crack. Comparisons are made between all eight procedures with the finding that the methods can be ranked in order of decreasing conservatism and ease of application as follows: 1–maximum stress, 2–linear envelope, 3–linearization over the crack length, 4–polynomial method, and 5–singularity element method. Good agreement is found between the last three of these methods. The remaining three methods produce nonconservative results.

An improved boundary element formulation for calculating stress intensity factors: Application to aerospace structures

1987 ◽  
Vol 22 (4) ◽  
pp. 203-207 ◽  
Author(s):  
M H Aliabadi ◽  
D P Rooke ◽  
D J Cartwright
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Boundary Element ◽  
Stress Intensity Factors ◽  
Crack Tip ◽  
Stress Fields ◽  
Element Formulation ◽  
Intensity Factors ◽  
Singular Stress ◽  
Singular Stress Field

In order to compute stress intensity factors accurately, the standard boundary element method is modified to take explicit account of the singularity in the stresses at a crack-tip. The known expansion terms of the crack tip displacement and stress fields are subtracted to remove the numerical difficulties associated with the representation of a singular stress field at the crack-tip. Hence the accuracy of calculation is much improved, without appreciably increasing the amount of computation involved. Furthermore, the stress intensity factor is directly obtained as a part of a solution and no extrapolations are required. The improved formulation is applied to a configuration, which is representative of a part of the wing in a civil transport aeroplane. This configuration consists of a pair of circular cut-outs (supply ports) near to which smaller holes exist; these small holes are particularly susceptible to cracking.

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