Search

Your search keyword '"Lee, Sanboh"' showing total 74 results
Start Over Author "Lee, Sanboh" Publisher elsevier bv
74 results on '"Lee, Sanboh"'

10. Edge dislocation dipoles near a semi-infinite crack tip

Author

Lee Sanboh and Wang Shing-Dar

Subjects
Materials science, Condensed matter physics, business.industry, Mechanical Engineering, Magnetic monopole, Fracture mechanics, Edge (geometry), Rotation, Strain energy, Condensed Matter::Materials Science, Dipole, Optics, Mechanics of Materials, Peierls stress, General Materials Science, business, Stress intensity factor
Abstract

Based on the result of an edge dislocation monopole near a semi-infinite crack tip, the elastic interaction between an edge dislocation dipole and a semi-infinite crack is investigated. The strain energy of the edge dipole is derived. Two kinds of flipping energy are discussed: edge dislocations gliding along their slip planes and edge dislocations rotating with their center as the rotating axis. The flipping energy of gliding is lower than that of rotation. In addition to the image force, the image torque with respect to the dipole center is also significant. The stress intensity factor due to applied load for edge dislocation dipole emission is proposed. In addition, the edge dislocation dipole and edge dislocation monopole near the semi-infinite crack are compared.

Published
1993
Full Text
View/download PDF

13. Screw dislocation in the two-phase isotropic thin film of an interfacial crack

Author

Lee Sanboh and C.L. Chang

Subjects
Materials science, Mechanical Engineering, Crack tip opening displacement, Crack growth resistance curve, Stress field, Shear modulus, Crack closure, Mechanics of Materials, Peierls stress, Forensic engineering, General Materials Science, Composite material, Dislocation, Stress intensity factor
Abstract

The screw dislocation in the two-phase isotropic thin film of an interfacial crack has been investigated. The stress field, stress intensity factors at the crack tip and for dislocation emission, crack extension force, strain energy and the image force on the dislocation are obtained and found to be related to the thickness and effective shear modulus. The effect of size on fracture is pronounced when the thickness is smaller than the distance between dislocation and crack tip by a factor of 1000. The effect of the second phase on fracture is pronounced when μ (2) /μ (1) is in the range from 0.01 to 100. Newton's third law is proved to be valid for any thickness and shear modulus ratio. This result can be reduced to three special cases.

Published
1990
Full Text
View/download PDF

35. Interaction of an edge dislocation with an elliptical hole in a rectilinearly anisotropic body

Author

Chen, Bi-Trong, Zhang, Tongyi, Lee, Sanboh, Chen, Bi-Trong, Zhang, Tongyi, and Lee, Sanboh

Abstract

Following Sih's approach to the rectilinearly anisotropic plane strain elasticity, the present work analytically studies the stress field, image force and shielding effect of an edge dislocation in the vicinity of an elliptical hole. The results show that the dislocation source plays a very important role in the interaction. The stress field and the image force are more pronounced for the edge dislocation emitted from the elliptical hole than that for the edge dislocation come elsewhere. Tungsten (W) single crystal is used to simulate an isotropically elastic material, and iron (Fe), copper (Cu) and zinc (Zn) to represent the anisotropic bcc, fee and hcp structures, respectively. The effects of anisotropy are the most pronounced on the stress component sigma(zz) among all stress components. When a dislocation is emitted from the hole and moves far away, the interaction between the dislocation and the hole behaves like that between the real dislocation and an image dislocation located at the center of the hole having the same Burgers vector but with an opposite sign as the real. However, there is no interaction at all between a dislocation and the hole if the dislocation come elsewhere is located far away from the hole. In general, the anisotropy produces an abnormal image force. When the dislocation is located on the x-axis and has a Burgers vector parallel to the x-axis, an abnormal image force is induced along the y-axis, while an abnormal image force is induced along the x-axis when the dislocation is located on the y-axis and has a Burgers vector parallel to the y-axis. The solution of an edge dislocation interacting with an elliptical hole in an infinite isotropic, elastic body is provided in an Appendix. (C) 1999 Elsevier Science Ltd. All rights reserved.

Published
1999

Catalog

Books, media, physical & digital resources
See catalog results