Effect of a linear parameter on the brittle fracture of an elastic layer with a circular hole

The effect of a hole radius in an elastic layer on a critical external load at the moment of the onset of fracture, determined by the energy criterion, is investigated. Using the free energy flow through an interaction arc as a fracture criterion makes it possible to describe the dependence of the critical external load on the hole radius. The length of the interaction arc constructed in the vicinity of a free energy peak point is determined using a linear parameter. The introduced linear parameter for a polymethyl methacrylate layer is obtained using known experimental data. The maximum value of the linear parameter can be taken as a material constant.