Dynamic Analysis of Abrasive Filaments in Contact with Different Workpiece Geometries

Abrasive brushes are often used for surface finishing and deburring and consist of a brush body with fixed, highly flexible abrasive filaments. During the brushing process the highly flexible abrasive filaments deform tangentially and axially and adapt to the shape of the workpiece. The contact behaviour of abrasive brushes in the machining process is very complex and has been insufficiently investigated so far. Abrasive brushes consist of a brush body with fixed, highly flexible abrasive filaments and are often used for surface finishing and deburring. During the brushing process, the highly flexible abrasive filaments deform tangential and axial and adapt to the shape of the workpiece. The mentioned contact behavior of the abrasive brush during the machining process is complex, and has not yet been sufficiently investigated. To better understand the contact behavior and, thus, the brushing process, a model of an abrasive filament is proposed in this study. The model describes the dynamic behavior of a single filament in contact with different workpiece geometries. The filament is discretized into a multi-body system of rigid links connected with rotational springs and rotational dampers, and the workpiece is approximated by using a polynomial. The contact of the multi-body system representing the filament with the surface of the workpiece is described by using Hertz's theory of elastic contact and Coulomb's law of friction. Based on this, a system of equations of motion for the multi-body system is obtained by using Lagrangian mechanics. A numerical solution of the equation of motion system was calculated by using experimentally determined material and contact properties of the filament as a composite of a plastic matrix and abrasive grains. A comparison of the calculated results with experimental data yielded satisfactory agreement for the contact between the filament and different workpiece geometries.