On the Doubly Regenerative Stability of a Grinder: The Effect of Contact Stiffness and Wave Filtering

Abstract

In the interest of acquiring a physical understanding of the causes and growth of chatter in grinders, past studies of doubly regenerative stability by the author (Thompson, 1974, 1977; Hahn and Thompson, 1977) looked at unnaturally high workpiece rotational speeds, excluded the contribution of cutting zone contact stiffness, and did not consider the effect of workpiece wave filtering. By incorporating these effects into the past referenced work, this paper attempts to close the gap between basic understanding and actual grinder behavior. It is known that at low speeds chatter involving large numbers of lobe pairs is excited. This leads to a diffuse frequency spectrum. It is further shown that the effect of finite contact stiffness is to improve stability and that workpiece wave filtering has no effect on basic stability, but leads to self-limiting chatter. The approach to wave filtered quasistability is accompanied by a lowering of chatter frequency.

Experimental Investigations and Numerical Simulations of the Relationship between Tool Geometry and Cutting Chatter

“…Besides, the chatter sound of case (3) and case (4) are audible. The results of case (3) and case (4) show that a decrease in rake angle and an increase in clearance angle will greatly increase the degree of the cutting chatter and decrease the cutting stability.. Tool geometry is the first essential factor of the occurrence of cutting chatter [5] .…”

Regenerative chatter in self-interrupted plunge grinding

“…; s 16 to track the multiple-delay effects of the workpiece regeneration. For an accurate simulation of the grinding dynamics, more regions and time delays are required, and then the analysis with the DDEs becomes a kinematic relationship similar to those studied by Thompson [29][30][31][32][33], Weck [38], and Li and Shin [14]. A similar investigation on a turning process was carried out by Liu et al [16], who divided the workpiece profile into 600 segments for the simulation of the chatter with multiple-delay effects.…”

“…In regard to the grinding chatter, Thompson in [29][30][31][32][33] carried out a series of studies on regenerative effects caused by the surfaces of both the workpiece and the grinding wheel. Kinematic models and time domain simulations were used in these investigations and other works, e.g.…”

Non-linear analysis and quench control of chatter in plunge grinding

“…Compared with the turning or the milling, the grinding regeneration exists in both workpiece and grinding wheel surfaces [15], called a doubly regenerative problem [16]. The feature of the grinding was captured by Thompson, who used a kinematic model to discuss the stability of plunge grinding [17][18][19][20]. Afterwards, Li and Shin [21] improved this model and obtained more precise results, by using numerical simulations.…”