Collinear Internal Cracks and Edge Crack in a Semi-Infinite Sheet Subjected to Arbitrary Tractions

1995 ◽  
Vol 117 (3) ◽  
pp. 256-259 ◽  
Author(s):  
T. Nishimura
Keyword(s):  
Stress Intensity ◽  
Numerical Analysis ◽  
Integral Equations ◽  
Stress Intensity Factors ◽  
Edge Crack ◽  
Mutual Interaction ◽  
Internal Crack ◽  
Intensity Factors ◽  
Plate Edge

The stress intensity factors are calculated for collinear internal cracks and an edge crack in a semi-infinite sheet subjected to arbitrary tractions. Analysis is conducted by formulating the integral equations of tractions along the plate edge and crack surfaces. The accuracy is checked with known results in the literature. Then, the numerical analysis is used to establish the stress intensity factors for various sizes of the edge crack and internal cracks in tension. Also, the stress intensity factors are calculated for the edge crack and internal crack subjected to typical distributed loadings, and the effects of mutual interaction between the cracks are presented.

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.

Stress Intensity Factors of Multiple Cracked Sheet With Riveted Stiffeners

1991 ◽  
Vol 113 (3) ◽  
pp. 280-284 ◽  
Author(s):  
T. Nishimura
Keyword(s):  
Stress Intensity ◽  
Integral Equations ◽  
Stress Intensity Factors ◽  
Fredholm Integral Equations ◽  
Multiple Cracks ◽  
Basic Solution ◽  
Intensity Factors ◽  
Single Crack ◽  
Numerical Examples ◽  
Unknown Density

A new method is proposed for analyzing the stress intensity factors of multiple cracks in a sheet reinforced with riveted stiffeners. Using the basic solution of a single crack and taking unknown density of surface tractions and fastener forces, Fredholm integral equations and compatibility equations of displacements among the sheet, fasteners, and stiffeners are formulated. After solving the unknown density, the stress intensity factors of multiple cracks in the sheet are determined. Some numerical examples are analyzed.

Transient Stress Intensity Factors of an Interfacial Crack Between Two Dissimilar Anisotropic Half-Spaces, Part 2: Fully Anisotropic Materials

1984 ◽  
Vol 51 (4) ◽  
pp. 780-786 ◽  
Author(s):  
A.-Y. Kuo
Keyword(s):  
Stress Intensity ◽  
Integral Equations ◽  
Singular Integral ◽  
Stress Intensity Factors ◽  
Jacobi Polynomials ◽  
Mathematical Problem ◽  
Stress Singularity ◽  
Interfacial Crack ◽  
Singular Integral Equations ◽  
Intensity Factors

Dynamic stress intensity factors for an interfacial crack between two dissimilar elastic, fully anisotropic media are studied. The mathematical problem is reduced to three coupled singular integral equations. Using Jacobi polynomials, solutions to the singular integral equations are obtained numerically. The orders of stress singularity and stress intensity factors of an interfacial crack in a (θ(1)/θ(2)) composite solid agree well with the finite element solutions.

Dynamic Stress Intensity Factors for an Inclined Subsurface Crack

1984 ◽  
Vol 51 (4) ◽  
pp. 773-779 ◽  
Author(s):  
W. Lin ◽  
L. M. Keer ◽  
J. D. Achenbach
Keyword(s):  
Free Surface ◽  
Stress Intensity ◽  
Integral Equations ◽  
Stress Intensity Factors ◽  
Wave Equations ◽  
Harmonic Excitation ◽  
Subsurface Crack ◽  
Intensity Factors ◽  
Dynamic Stress Intensity Factors ◽  
Time Harmonic

Stress intensity factors are computed for an inclined subsurface crack in a half space, whose surface is subjected to uniform time-harmonic excitation. The problem is analyzed by determining displacement potentials that satisfy reduced wave equations and specified boundary conditions. The formulation of the problem leads to a system of coupled integral equations for the dislocation densities. The numerical solution of the integral equations leads directly to the stress intensity factors. Curves are presented for the ratios of the elastodynamic and the corresponding elastostatic Mode-I and Mode-II stress intensity factors for various frequencies and various inclinations of the crack with the free surface. For small angles of inclination with the free surface and large crack length-to-depth ratios, strong resonance vibrations of the layer between the crack and the free surface may arise.

Numerical Method for Determining Stress Intensity Factors of an Interior Crack in a Finite Plate

1971 ◽  
Vol 93 (4) ◽  
pp. 685-690 ◽  
Author(s):  
W. K. Wilson
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Stress Function ◽  
Outer Boundary ◽  
Normal Derivative ◽  
Crack Edge ◽  
Rectangular Plates ◽  
Airy Stress Function ◽  
Intensity Factors ◽  
Plate Edge

A boundary collocation method for estimating the stress intensity factors for a through-thickness interior crack in a plate of arbitrary geometry and arbitrary in-plane loading on the plate outer-boundary and crack surfaces is presented. The collocation is carried out on an Airy stress function which is derived from a previously given complex stress function. Various types of boundary collocation procedures are investigated. It is shown that collocation on the Airy stress function and its normal derivative gives the most accurate results. The method is applied to rectangular plates containing center cracks of arbitrary angular orientation. A number of plate edge and crack edge loading conditions are analyzed. The stress intensities calculated by this method compare very favorably with existing solutions for cases in which such solutions are available.

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