A rod or beam is one of the most widely used members in engineering construction.
Such members must be properly designed to resist the applied loads. When subjected
to antiplane (longitudinal) shear and torsional loading, homogeneous, isotropic, and
elastic materials are governed by the Laplace equation in two dimensions under the
assumptions of classical continuum mechanics, and are considerably easier to
solve than their three-dimensional counterparts. However, when using the
finite element method in conjunction with linear elastic fracture mechanics,
crack nucleation and its growth still pose computational challenges, even
under such simple loading conditions. This difficulty is mainly due to the
mathematical structure of its governing equations, which are based on the local
classical continuum theory. However, the nonlocal peridynamic theory is free of
these challenges because its governing equations do not contain any spatial
derivatives of the displacement components, and thus are valid everywhere in
the material. This study presents the peridynamic equation of motion for
antiplane shear and torsional deformations, as well as the peridynamic material
parameters. After establishing the validity of this equation, solutions for specific
components that are weakened by deep edge cracks and internal cracks are
presented.