Application of Solid Modeling Techniques for Geometric Simulation of Surface Topography in Boring Operations

The quality of machined surface and the dynamic stability of cutting process are directly correlated to the dynamic cutting force, which itself depends on the geometry of engagement between the cutting tool and workpiece that defines the dynamic chip thickness. The surface topography is one of the most important figures of merit for evaluation of performance in machining processes, which is influenced by the geometry of cutting edge, the kinematics of cutting operation, the flexibility of machine tool structure and the resulting structural vibrations during the chip formation process. In order to define the instantaneous engagement between the cutting tool and workpiece precisely, all these factors should be taken into account. In this paper, the mechanics, dynamics and geometry of boring operations is considered for development of a virtual simulation model by using the solid modeling techniques. The dynamic parameters of boring bar are defined by modal analysis experiments, and the cutting force coefficients are experimentally identified by conducting mechanistic cutting tests. The experimental cutting tests are conducted in both absolutely stable and unstable cutting conditions. In order to validate the developed model, firstly, the simulated cutting forces are compared with the corresponding experimental results. Secondly, the simulated topography of machined surface in both stable and unstable cutting conditions is compared with the SEM images from real cut surfaces. The presented geometric simulation model shows a remarkable potential for exact simulation of boring operations in stable and unstable conditions.