Originally Posted by
canid
would you believe i know what a knife grind is.
more specifically, i also know what an edge is, what a bevel is, and how they work.
an edge is nothing more than an abstract line segment. for a given intersection of n-faces, the edge is the point at which they converge. any discontinuity in this segment results in the creation of futher faces, and the formation of additional edges.
cutting ability is created by action of shear stress of one or more edges [tangential?] to a solid face.
very roughly speaking, the resistance to cutting should be a product of the shear strength of the solid, the length of all edge segments in contact and the coeficient of kinetic friction of the faces in contact [ increasing with the surface area of faces in contact with the face to be sheared].
now; since the shortest distance between two points is a line segment, the fewer discontinuities in an ideal edge segment, the lesser the length of the total edge segments, and the lesser the surface area of faces in contact with the solid to be sheared.
because solids to be cut are elastic, and deform to one degree or other with the application of force, the rate at which the surface area and lengths of edge segments increases for a given degree of deformation can be minimized by changing the angle of bevel as you move back from the edge [which we've established is actualy a number of edge segments connecting many faces]. this is what i mean by reducing drag.
singe the edge itself is only an abstract segment, the angle of convergence is broken by any discontinuity, ragardless of whether the edge angle is 90°, 45°, etc. the mass behind it determines the forge required to deform it by a given amount, but the force required to deform it at all is pretty much the same.
it should be noted that i am essentially not college educated, and am largely self taught. i am only giving you an explanation of an aspect of mechanics to the best understanding and ability. how you choose to take it is entirely up to you. you've already got your own education and understanding, and i acknowledge that.