  Crack-tip stress evaluation has always been a problem in the frame of
classical elasticity theory. Peridynamics has been shown to have great
advantages in dealing with crack problems. In the present study, we present a
peridynamic crack-tip stress evaluation method for multi-scale Griffith crack
subject to tensile loading. The bond-based peridynamics is used to calculate
the displacement field. Non-local deformation gradient definition from
non-ordinary state-based peridynamics is used for stress calculation. Besides,
a scale factor is introduced for evaluating crack-tip stress of multi-scale
Griffith crack. Numerical results compared with Eringen's results show that
this peridynamic crack-tip stress evaluation method is valid for multi-scale
cracks, and with the change of distance of material points, the evaluated
crack-tip stress tends to be stable.
