The atoms surrounding an edge dislocation experience what kind (s) of strain (s) ?

Shear

Edge dislocation can occur if there is a missing atom. Crystalline material consists of array of atoms formed in lattice planes. In edge dislocation a defect where in an extra half plane of atom is introduced midway through crystal. This can also distort the nearby planes of the atom. With enough force applied joints and bonds will break and grain boundary will be reach. This is a complex dislocation because of its asymmetric nature.