Corner Crack at the Bore of a Rotating Disk

1976 ◽  
Vol 98 (4) ◽  
pp. 465-470 ◽  
Author(s):  
A. S. Kobayashi ◽  
N. Polvanich ◽  
A. F. Emery ◽  
W. J. Love
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Infinite Plate ◽  
Rotating Disk ◽  
Single Edge ◽  
Intensity Factors ◽  
Corner Crack ◽  
Aspect Ratios ◽  
Crack Problems ◽  
Corner Cracks

Stress intensity factors of corner cracks at the bore of a rotating disk are estimated from the stress intensity factor of a quarter-elliptical crack in a quarter infinite solid and pressurized by the hoop stress. Curvature effect of the bore is incorporated through a curvature correction factor derived from the stress intensity factors of a single edge-cracked bore in a large plate and a single edge-cracked semi-infinite plate. Stress intensity factors for quarter-elliptical cracks with crack aspect ratios of b/a = 0.2, 0.4, and 0.98 at crack depths of b/Ri = 0.1, 0.3 and 1.0 in a rotating disk with R0/Ri = 8 are determined. Application of the developed procedure to corner crack problems at a through-bolt hole is indicated.

Inner and Outer Cracks in Internally Pressurized Cylinders

1977 ◽  
Vol 99 (1) ◽  
pp. 83-89 ◽  
Author(s):  
A. S. Kobayashi ◽  
N. Polvanich ◽  
A. F. Emery ◽  
W. J. Love
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Finite Thickness ◽  
Internal Surface ◽  
Surface Cracks ◽  
Single Edge ◽  
Intensity Factors ◽  
Curvature Effects ◽  
Aspect Ratios ◽  
Dimensional Finite Element

Stress intensity factors of pressurized surface cracks at the internal surface and un-pressurized surface cracks at the external surface of an internally pressurized cylinder are estimated from stress intensity factors of a semi-elliptical crack in a finite-thickness flat plate. Curvature effects of the cylinder are determined by comparing two-dimensional finite element solutions of fixed-grip, single edge-notched plates and single edge-notched cylinders. Stress intensity factors for semi-elliptical cracks with crack aspect ratios of b/a = 0.2 and 0.98 at crack depths up to 80 percent of the cylindrical wall thickness are shown for internally pressurized cylinders with outer to inner diameter ratios, Ro/Ri, ranging from 10:9 to 5:4 for outer surface cracks and to 3:2 for inner surface cracks.

Comparative Studies of Stress Intensity Factors for Nozzle Corner Cracks and Flat Plate Cracks

2015 ◽  
Author(s):  
S. M. Smith ◽  
J. E. Holliday
Keyword(s):  
Stress Intensity ◽  
Flat Plate ◽  
Stress Intensity Factors ◽  
Elliptical Crack ◽  
Intensity Factors ◽  
Corner Crack ◽  
Finite Element Software ◽  
Corner Cracks ◽  
Transient Thermal ◽  
Elliptical Cracks

Using the finite element software Abaqus, the present study utilized explicit flaw modeling techniques to compute nozzle corner crack stress intensity factors for a range of semi-elliptical and sawcut cracks in a nozzle and semi-elliptical cracks in a flat plate. Additionally, a weight function method (WFM) for a semi-elliptical crack in a flat plate was evaluated. Stress intensity factors were computed for a number of loading conditions. A transient thermal stress analysis was performed for the nozzle explicit flaw models and discussed. Results of this study indicate that stress intensity factors at the bisecting position of the elliptical crack front from the flat plate model agree well with the analogous nozzle crack bisector position results and WFM solution.

Stress intensity factors for corner cracks at a hole under remote tension

1991 ◽  
Vol 7 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Zhao Wei ◽  
Wu Xueren ◽  
Yan Minggao
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Intensity Factors ◽  
Corner Cracks

Analysis of Multiple Rigid-Line Inclusions for Application to Bio-Materials

2007 ◽  
Author(s):  
Pawan S. Pingle ◽  
Larissa Gorbatikh ◽  
James A. Sherwood
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Crack Problem ◽  
Building Blocks ◽  
Duality Principle ◽  
Inclusion Problem ◽  
Multiple Cracks ◽  
Intensity Factors ◽  
Aspect Ratios ◽  
Rigid Line

Hard biological materials such as nacre and enamel employ strong interactions between building blocks (mineral crystals) to achieve superior mechanical properties. The interactions are especially profound if building blocks have high aspect ratios and their bulk properties differ from properties of the matrix by several orders of magnitude. In the present work, a method is proposed to study interactions between multiple rigid-line inclusions with the goal to predict stress intensity factors. Rigid-line inclusions provide a good approximation of building blocks in hard biomaterials as they possess the above properties. The approach is based on the analytical method of analysis of multiple interacting cracks (Kachanov, 1987) and the duality existing between solutions for cracks and rigid-line inclusions (Ni and Nasser, 1996). Kachanov’s method is an approximate method that focuses on physical effects produced by crack interactions on stress intensity factors and material effective elastic properties. It is based on the superposition technique and the assumption that only average tractions on individual cracks contribute to the interaction effect. The duality principle states that displacement vector field for cracks and stress vector-potential field for anticracks are each other’s dual, in the sense that solution to the crack problem with prescribed tractions provides solution to the corresponding dual inclusion problem with prescribed displacement gradients. The latter allows us to modify the method for multiple cracks (that is based on approximation of tractions) into the method for multiple rigid-line inclusions (that is based on approximation of displacement gradients). This paper presents an analytical derivation of the proposed method and is applied to the special case of two collinear inclusions.

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