  Non-singular dislocation continuum theories are studied. A comparison between
Peierls-Nabarro dislocations and straight dislocations in strain gradient
elasticity is given. The non-singular displacement fields, non-singular
stresses, plastic distortions and dislocation core shapes are analyzed and
compared for the two models. The main conclusion of this study is that due to
their characteristic properties, the non-singular displacement fields,
non-singular stresses and dislocation core shape of screw and edge dislocations
obtained in the framework of strain gradient elasticity are more realistic and
physical than the corresponding fields of the Peierls-Nabarro model. Strain
gradient elasticity of dislocations is a continuum dislocation theory including
a weak nonlocality within the dislocation core and predicting the size and
shape of the dislocation core. The dislocation core is narrower in the strain
gradient elasticity dislocation model than in the Peierls-Nabarro model and
more evenly distributed in two dimensions. The present analysis shows that for
the modeling of the dislocation core structure the non-singular dislocation
fields of strain gradient elasticity are the suitable ones.
