Interaction of two hard indenters in the cutting process of quasi-brittle materials

In this paper, an attempt is made to find some general relations for the microcutting process in brittle or quasi-brittle materials, under different hypotheses of microscopic failure behaviour. Fracture patterns in homogeneous brittle solids are obtained by the Finite Element Method in the framework of Linear Elastic Fracture Mechanics (LEFM). On the other hand, microstructural heterogeneities are taken into account by Lattice Model simulations. When two indenters are acting in parallel, their mutual distance plays an important role. If the indenters are very close, they behave like a unique large indenter, whereas if the distance is relatively large, their mechanical interaction vanishes. In addition, when the distance is approximately three or four times their radius, the mechanism of chipping (with formation of secondary chip between the two parallel grooves) can take place, improving the ratio of removed volume to spent energy and then the demolition ability of the two indenters.