A Korn-type inequality in SBD for functions with small jump sets

Abstract: We present a Korn-type inequality in a planar setting for special functions of bounded deformation. We prove that for each function in SBD$^2$ with sufficiently small jump set the distance of the function and its derivative from an infinitesimal rigid motion can be controlled in terms of the linearized elastic strain outside of a small exceptional set of finite perimeter. Particularly the result shows that each function in SBD$^2$ has bounded variation away from an arbitrarily small part of the domain.