Suppressing vibrations of machining processes in both feed and radial directions using an optimal control strategy: The case of interrupted cutting

Contribution to cylindrical grinding of interrupted surfaces of hardened steel with medium grit wheel

“…In this sense, the mechanical shocks become increasingly intensified due to impacts of the process which are originated by the couplings and uncouplings between the workpiece and grinding wheel. This will lead to fracture of bond and grits and, consequently, loss of grits cutting edges, thereby reducing cutting performance and adversely affecting surface finish [8,21]. In this current work, it was expected that the increase in number of grooves lead to more bond-grits fracture, but by the surface roughness and standard deviation values obtained, no influence of number of grooves was observed in the surface roughness.…”

“…Grinding can be considered as an interrupted machining process because of the thousands of cutting edges of the abrasive grains distributed throughout the grinding wheel that are not in constant contact with the workpiece material during the various revolutions per second of the abrasive wheel. According to Al-Zaharnah [8], interrupted cutting occurs when the tool is not in constant contact with the workpiece. This is the case of workpiece surfaces with grooves or also the grinding wheels having profiles, such as structurally profile grinding wheels and gear wheels, for instance.…”

“…In fact, there are many cutting edges on the tool, which alternate between cutting times (material removal phase) and times without contact with the workpiece (no material removal phase). This will lead to fluctuation in both thermal and mechanical load and adversely affect both tool and workpiece integrities, in especially the machined surface [8]. Furthermore, Kountanya [10] concluded that the cutting temperature developed in interrupted cutting is generally lower than in continuous cutting operations, because alternating periods of coupling and uncoupling provide cooling in the cutting zone.…”

The use of active materials for machining processes: A review

“…The results showed that their active tool holder improves the surface roughness of the workpiece by an average of 25% over a conventional tool holder. Al-Zaharnah [124] used two identical Tefenol-D actuators orthogonally located in both radial and feed directions in order to apply forces on the cutting tool in both directions independently. With the implementation of a Kalman estimator-based controller, vibration suppression of up to 30% was achieved.…”

An Approach of Vibration Control Based on the Design of Three DOFs Active Vibration Damping Platform

“…Ei-Sinawi et al developed optimal vibration control systems for turning operations by using active tool holder [11]. Zaharnah et al further developed optimal vibration control systems in both feed and radial directions to suppress the vibrations in cutting [12]. Zhang et al also use active magnetic bearing or piezo actuators to control spindle vibrations [13].…”