The interaction between a screw dislocation and a rigid line in a confocal elliptical inhomogeneity

• Published in: Applied mathematical modelling 2011-03, Vol.35 (3), p.985-995
• Main Authors: Fang, Q.H., Chen, J.M., Luo, Z.D., Song, H.P., Liu, Y.W.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.); Elliptical inhomogeneity; Exact sciences and technology; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Image force; Physics; Rigid line; Screw dislocation; Solid mechanics; Stress intensity factor; Structural and continuum mechanics; Structure of solids and liquids; crystallography
• ISSN: 0307-904X
• DOI: 10.1016/j.apm.2010.07.018

The interaction between a screw dislocation and an elastic elliptical inhomogeneity which contains a confocal rigid line is investigated. The screw dislocation is located inside either the elliptical inhomogeneity or the infinite matrix. By using the complex potential method, explicit series solutions of complex potentials are obtained. The image force acting on the screw dislocation and the stress intensity factor at the tip of the rigid line are derived. As a result, the analysis and discussion show that the influence of the rigid line on the interaction effects between a screw dislocation and an elliptical inhomogeneity is significant. The rigid line enhances the repulsive force exerted on the dislocation produced by the stiff inhomogeneity and abates the attractive force produced by the soft inhomogeneity. For the soft inhomogeneity, there is an unstable equilibrium position when the dislocation is inside the matrix and there is a stable equilibrium position when the dislocation is inside the inhomogeneity. The stress intensity factor contour around the rigid line tip shows that when a dislocation with positive burgers vector is in the upper half-plane, stress intensity factor will be positive; while in the lower half-plane, stress intensity factor will be negative; and in the x-axis, it will be zero. The absolute value of the stress intensity factor will increase when the dislocation approaches the tip of the rigid line. The stress intensity factor at the rigid line tip is enhanced by a harder matrix and abated by a softer matrix.