On stress singularity near the tip of a crack with surface stresses

In the framework of the simplified linear Gurtin–Murdoch surface elasticity we discuss a singularity of stresses and displacements in the vicinity of a mode III crack. We show that inhomogeneity in surface elastic properties may significantly affect the solution and to change the order of singularity. We also demonstrate that implicitly or explicitly assumed symmetry of the problem may also lead to changes in solutions. Considering various loading and symmetry conditions we show that the stresses may have logarithmic or square root singularity or be bounded in the vicinity of a crack tip.