Tuneable clamping table for chatter avoidance in thin-walled part milling

Self-Tuning Algorithm for Tuneable Clamping Table for Chatter Suppression in Blade Recontouring

“…As observed in (18), in milling processes with a dominant flexible direction, the limiting depth of cut without chatter is approximately given by the inverse of the oriented receptance function β 0 Re H 22 [21]. Therefore, the mean directional factor β 0 determines whether the negative real part of H 22 (positive directional factor, β 0 > 0) or the positive real part (negative directional factor, β 0 < 0) describes the limiting depth of cut curves.…”

“…Purely mechanical assemblies based on preloaded elastomers [24], position-adjustable moving masses [25,26] or rotary springs [27][28][29][30] have been proposed to control the stiffness of the damper. Regarding the damping, eddy current modules have been proven to be a reliable alternative for obtaining a nearly-ideal and adjustable viscous damping [18,28,29]. The use of electrorheological and magnetorheological fluids to simultaneously control the stiffness and damping of the device has also been investigated [31], with application over vibration attenuation in thin walled part milling as well [32,33].…”

“…The viscous damping of the table is provided by the eddy current damping modules under the table, whose damping level can be adjusted by modifying the immersion of the conductive plates inside the magnetic field created by permanent magnets. Further details on its mechanical design and conception can be found in [18].…”

“…As opposed to the in-parallel architecture of regular TMDs, the tuneable clamping table (TCT [18]) is an application case of mode tuning with an in-series architecture, which can increase the damping of the critical mode by tuning a highly damped and controlled mode close to the targeted mode in the frequency band. Its in-series architecture provides the capability to achieve the tuning between the controlled mode and the critical mode of the blade with a universal clamping system and without any direct intervention in the cutting zone.…”

“…Nevertheless, in mode tuning devices fine tuning is essential to achieve a maximum increase in dynamic stiffness. To this effect, the algebraic expressions for optimal H ∞ tuning for a TCT have already been developed [18], which are the equivalent-but different-to classical TMD amplitude tuning methodologies [19,20]. When the aim is to maximize milling stability, the aforementioned strategies are no longer optimal [21], and specific tuning procedures based on the optimization of the real part of the receptance function have to be applied [22,23].…”