3.3.1 Introduction
The determination of the grinding wheel topography can be divided into static, kinematic, and dynamic methods [Bruecher 1996]:
• Static methods—All abrasive grains on the surface of the grinding tool are considered. The kinematics of the grinding process is not taken into account.
• Dynamic methods—In this process, the number of actual abrasive grain engagements are measured. The active cutting edge number is the totality of cutting edges involved in the cutting process.
• Kinematic methods—Kinematic methods combine the effects of the kinematics of the process with the statically determined grain distribution for the specification of microkinematics at the single grain, that is, for the determination of cutting parameters.
3.3.2 Static Methods
If static assessment methods are used, basically all cutting edges in the cutting area are included in the topography analysis. There is no distinction, whether a cutting edge of the grinding process is actively involved or not in the cutting process. Static processes are independent of the grinding conditions [Shaw and Komanduri 1977; Verkerk 1977].
Figure 3.2 shows a schematic section of a cutting surface of a grinding wheel. All abrasive grains protruding from the bond have cutting edges—the so-called static cutting edges. Since grains usually have more than one cutting edge, the distance between the static cutting edges does not correspond to the average statistical grain separation on the grinding wheel. Therefore, instead of the distance between the static cutting edges, the number of cutting edges is specified per unit length, that is, the static cutting edge number Sstat, the cutting edge density per surface unit Nstat, or the number per unit volume of the cutting area Cstat [Daude 1966, Lortz 1975, Kaiser 1977, Shaw and Komanduri 1977, Verkerk 1977, Rohde 1985, Treffert 1995, Marinescu et al. 2004].
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FIGURE 3.2 Static cutting edges. (From Koenig and Klocke 1996. With permission.) |
