On the Determination of Stress Intensity Factors for Cracked Thick Cylinders

1983 ◽  
Vol 22 ◽  
Author(s):  
A P Parker ◽  
C P Andrasic
Keyword(s):  
Stress Intensity ◽  
Internal Pressure ◽  
Wall Thickness ◽  
Stress Intensity Factors ◽  
Material Removal ◽  
Simple Expression ◽  
Stress Fields ◽  
Intensity Factors ◽  
Fatigue Lifetime

ABSTRACTThe authors have previously published stress intensity (K) solutions for singly and multiply cracked thick cylinders with internal pressure and autofrettage stress fields. In this paper a method of obtaining K values for intermediate radii ratios is proposed. The method involves an approximate superposition procedure which models the removal (or addition) of cylinder material and is based on the nearest available radii ratio. The procedure is exact for very short crack lengths, and generally gives answers within 5% at crack lengths up to 20% of wall thickness (wherein most of the fatigue lifetime is expended) after removal of 20% of the wall thickness. A simple expression is given for the anticipated change in fatigue lifetime resulting from material removal.

Photoelastic determination of mixed-mode stress intensity factors for inclined semi-circular cracks in thin tubes

1989 ◽  
Vol 24 (2) ◽  
pp. 83-94 ◽  
Author(s):  
T H Hyde ◽  
N A Warrior
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Crack Depth ◽  
Stress Fields ◽  
Crack Orientation ◽  
Intensity Factors ◽  
Analysis Of Results ◽  
Mode Stress ◽  
Crack Position

Metal shims have been used to produce internal and external, semicircular, surface, crack-like flaws in cast, photoelastic models of thin tubes. The effects of crack depth, crack orientation, crack inclination, and crack position (i.e., internal or external) have been determined from the analysis of results from 69 slices taken from 24 ‘crack’ types. It has been shown that by taking eleven terms in the solutions for the crack-tip stress fields, rather than taking only the singular solution, more accurate stress-intensity factors are obtained.

DETERMINATION OF RESIDUAL STRESSES AND STRESS INTENSITY FACTORS BY REMOVING LOCAL MATERIAL

2017 ◽  
Vol 48 (4) ◽  
pp. 377-398
Author(s):  
Svyatoslav Igorevich Eleonskii ◽  
Igor Nikolaevich Odintsev ◽  
Vladimir Sergeevich Pisarev ◽  
Stanislav Mikhailovich Usov
Keyword(s):  
Stress Intensity ◽  
Residual Stresses ◽  
Stress Intensity Factors ◽  
Intensity Factors ◽  
Local Material

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.

Experimental Determination of KI for Short Internal Cracks

2001 ◽  
Vol 68 (6) ◽  
pp. 937-943 ◽  
Author(s):  
K. Bearden ◽  
J. W. Dally ◽  
R. J. Sanford
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Edge Crack ◽  
Series Solution ◽  
Experimental Studies ◽  
Experimental Methods ◽  
Internal Crack ◽  
Intensity Factors ◽  
Mode Stress

Since the pioneering discussion by Irwin, a significant effort has been devoted to determining stress intensity factors (K) using experimental methods. Techniques have been developed to determine stress intensity factors from photoelastic, strain gage, caustics, and moire´ data. All of these methods apply to a relatively long single-ended-edge crack. To date, the determination of K for internal cracks that are double-ended by experimental methods has not been addressed. This paper describes a photoelastic study of tension panels with both central and eccentric internal cracks. The data recorded in the experiments was analyzed using a new series solution for the opening-mode stress intensity factor for an internal crack. The data was also analyzed using the edge-crack series solution, which is currently employed in experimental studies. Results indicated that the experimental methods usually provided results accurate to within three to five percent if the series solution for the internal crack was employed in an overdeterministic numerical analysis of the data. Comparison of experimental results using the new series for the internal crack and the series for an edge crack showed the superiority of the new series.

Experimental Determination of Side Boundary Effects on Stress Intensity Factors in Surface Flaws

1975 ◽  
Vol 97 (1) ◽  
pp. 45-51 ◽  
Author(s):  
M. Jolles ◽  
J. J. McGowan ◽  
C. W. Smith
Keyword(s):  
Stress Intensity ◽  
Crack Length ◽  
Taylor Series ◽  
Stress Intensity Factors ◽  
Taylor Series Expansion ◽  
Correction Method ◽  
Intensity Factors ◽  
Surface Flaws ◽  
Plate Width

A technique consisting of stress-freezing photoelasticity coupled with a Taylor Series Expansion of the maximum local in-plane shearing stress known as the Taylor Series Correction Method (TSCM) is applied to the determination of stress intensity factors (SIF’s) in flat bottomed surface flaws of flaw depth/length ratios of approximately 0.033. Flaw depth/thickness ratios of approximately 0.20 and 0.40 were studied as were plate width/crack length ratios of approximately 2.33 and 1.25, the former of which corresponded to a nearly infinite width. Agreement to well within 10 percent was found with the Rice-Levy and Newman theories using a depth-modified secant correction and equivalent flaw depth/length ratios. The Shah-Kobayashi Theory, when compared on the same basis, was lower than the experimental results. Using a modified net section stress correction suggested by Shah, agreement with the Shah-Kobayashi Theory was greatly improved but agreement with the other theories was poorer. On the basis of the experiments alone, it was found that the SIF was intensified by about 10 percent by decreasing the plate width/crack length from 2.33 to 1.25.

scholarly journals Determination of mode I stress intensity factors of complex configurations using strain gages

2008 ◽  
Vol 3 (7) ◽  
pp. 1239-1255 ◽  
Author(s):  
Sanda Swamy ◽  
Manda Srikanth ◽  
Kondepudi Murthy ◽  
Puthuveettin Robi
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Mode I ◽  
Strain Gages ◽  
Intensity Factors
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