A geometric model of decohesion in solid continua

A modeling framework for material separation is proposed within the broad class of cohesive-type models. A key feature of the proposed framework is that the cohesive tractions are governed by a separate boundary-value problem defined on the separation surface, rather than by a traction-separation rule or other constitutive construct. The traction BVP incorporates a boundary condition intended to enforce continuity of the strain field at the separation front, thus rendering the material state bounded and continuous at the front. The phenomenology of material separation is governed by a rupture function, which can depend arbitrarily on the bulk material state. The rupture function, which is evaluated on the separation front, delineates the conditions for, and direction of, material separation. A linearly-elastic analytical solution using the new theory is provided to illustrate the functioning of the theory, including the regularizing effect of the cohesive traction.