Force on a screw dislocation in a multiphase laminated structure

Abstract

The force on a screw dislocation in a multiphase laminated elastic structure is determined, both as an infinite integral and as a sum of multiple image terms. When the dislocation is near an interface, it is found that dislocation mobility is largely dependent on the ratio of the rigidities of the adjacent materials, and the perpendicular distance of the dislocation from the interface becomes the important length scale. When the dislocation is far from the interface layers, it is found that a combination of an odd number of alternate strata of two different materials has a stabilizing influence on the dislocation. Further, if two dissimilar semi-infinite planes are separated by any number of dissimilar thick layers, then the force on a screw dislocation at large distances is independent of the physical properties of the interface layers.

On screw dislocation in a multiphase lamellar inclusion

“…Consistent with the condition for validity of a multinomial series expansion, the series F(h) converges if |ζ | < 1, where ζ = ζ 1 + ζ 2 + ζ 3 + ζ 4 + ζ 5 . As confirmed by numerical computation [13], the terms of the series F(h) continually diminish in strength with increasing distances of the images from the plane boundaries and the series converges, requiring only a finite number of terms to obtain a good approximation.…”

“…If a screw dislocation of strength (0, 0, b) lies at the point (h, 0) in the semi-infinite phase S 1 of shear modulus µ 1 , the image force is given by [13] …”

Time-harmonic dislocations in a multilayered transversely isotropic magneto-electro-elastic half-space

“…Similar to any structural material, it is important to understand the strengthening and hardening mechanisms in the smart MEE materials (Ogbonna, 2014), which are strongly influenced by dislocations, among other factors (Gharahi et al, 2018). In other words, stability (or mobility) of dislocations could change the response of any inhomogeneous solid structure and thus influence its strength (material properties) and consequently its service life (Gharahi et al, 2018; Ranjan et al, 1987).…”

A screw dislocation in a three-phase composite strip

“…Problems concerning the determination of elastic fields induced by dislocations interacting with multiple boundaries and interfaces in multilayered structures are challenging yet continue to attract the interest of many researchers (see, for example, [1][2][3][4][5][6][7][8][9][10][11]). These studies are essential for a better understanding of the mechanical performance of these composite structures as well as thin films.…”