  A generalized disclination (g.disclination) theory [AF15] has been recently
introduced that goes beyond treating standard translational and rotational
Volterra defects in a continuously distributed defects approach; it is capable
of treating the kinematics and dynamics of terminating lines of elastic strain
and rotation discontinuities. In this work, a numerical method is developed to
solve for the stress and distortion fields of g.disclination systems. Problems
of small and finite deformation theory are considered. The fields of a single
disclination, a single dislocation treated as a disclination dipole, a tilt
grain boundary, a misfitting grain boundary with disconnections, a through twin
boundary, a terminating twin boundary, a through grain boundary, a star
disclination/penta-twin, a disclination loop (with twist and wedge segments),
and a plate, a lenticular, and a needle inclusion are approximated. It is
demonstrated that while the far-field topological identity of a dislocation of
appropriate strength and a disclination-dipole plus a slip dislocation
comprising a disconnection are the same, the latter microstructure is
energetically favorable. This underscores the complementary importance of all
of topology, geometry, and energetics in understanding defect mechanics. It is
established that finite element approximations of fields of interfacial and
bulk line defects can be achieved in a systematic and routine manner, thus
contributing to the study of intricate defect microstructures in the scientific
understanding and predictive design of materials. Our work also represents one
systematic way of studying the interaction of (g.)disclinations and
dislocations as topological defects, a subject of considerable subtlety and
conceptual importance [Mer79, AMK17].
