What is the role of dislocations in plastic deformation

Write the constitutive law for a material with linear elastic anisotropic behavior under mechanical loading.

The overall fracture strength of glass may be increased by etching away a thin surface layer. It is thought that the etching can alter the surface crack geometry. Calculate the ratio of the etched and original crack tip radii if the fracture strength increases by a factor of 8 when 48 percent of the crack length is removed.

Outline the differences between brittle and ductile materials and explain how the failure mechanism for brittle and ductile materials account for the different features observed on fracture sur