| A continuum mechanics model (CMM) for orthogonal cutting has successfully been developed, calibrated, and verified through a total of 90 statistically designed cutting tests for O1 and L6 tool steels. The model in premise is that, along a family of assumed streamlines, the velocity, Eulerian strain, Eulerian strain rate, and deformation rate distributions, based on the finite deformation theory of continuum mechanics, can be analytically obtained. As a result, once the material constitutive equation energy consumed in the cutting process may be represented in terms of a few parameters. If the material behavior is dependent on temperature, a simple iterative incremental method is used to predict the temperature on the shear plane as well as the average chip temperature. Finally, these model parameters are predicted by minimizing the total rate of work using a nonlinear optimization method. For a wide range of cutting conditions for both O1 and L6 tool steels, the predicted cutting forces and shear angles agree very well with experimental measurements from cutting tests.; The material constitutive equations for O1 and L6 tool steels were based on a set of Hopkinson bar tests. The dynamic mechanical behavior of these two tool steels are dependent upon strain rate. In cutting tests, the thermal softening effects are also significant. From this work, it has been shown that the material constitutive equations calibrated by material tests can be applied to the prediction of the cutting forces and other measurable variables with sufficient accuracy in an orthogonal cutting process.; An important experimental observation in orthogonal cutting is that the shear angle increases when there is an increase in the undeformed chip thickness. This behavior is also adequately represented by the continuum mechanics model for orthogonal cutting process. The relationships of cutting pressures and shear angle to the cutting conditions predicted using the continuum mechanics model are also consistent with the experimental measurements. |
