Cutting resistance of polymeric materials: experimental and theoretical investigation

In the present paper, an experimental campaign is carried out with reference to the steady state propagation of an existing cut in polymeric plates, ranging from glassy to soft polymers. The steady state propagation is investigated by considering a commercial cutting tool under different insertion velocities of the blade. Full-field finite strain maps are experimentally recorded by means of digital image correlation technique, along with the recording of the insertion force vs displacement curve. It is shown that the cutting resistance is dependent on the fracture toughness of the target material and on the sharpness of the cutting tool. Different scenarios of steady state cut propagation are observed if either a relatively blunt or a relatively sharp blade penetrates in the material. Alternative blade sharpness parameters can be used to discriminate the different conditions of cut propagation observed in the experiments. A theoretical interpretation of the experimental outcomes is provided.