The Delft Sand, Clay & Rock Cutting Model, 2019a

The Delft Sand, Clay & Rock Cutting Model.
Resulting in:
1
2
2
4 2
(8-60)
With:
1
sin
sin cos
(8-61)
2
Substituting equation (8-61) in equation (8-55) gives for the force Fc:
Fc
T h w
1 sin
2sin
(8-62)
The horizontal component of the cutting force Fch is now:
2sin
Fch
T
h w cos
1
sin
(8-63)
The vertical component of this cutting force Fcv is now:
2sin
Fcv
T
h w sin
1
sin
(8-64)
8.3.3. The Model of Evans used for a Pick point.
In the case where the angle ε equals the angle α, a pick point with blade angle 2·α and a wear flat can be simulated
as is shown in Figure 8-23. In this case the equations become:
2sin
Fc
Th w
1 sin 2
(8-65)
The horizontal component of the cutting force Fch is now:
2sin
Fch
T
h w cos
1
sin 2
(8-66)
The vertical component of this cutting force Fcv is now:
2sin
Fcv
T
h w sin
1
sin 2
(8-67)
For the force R (see equation (8-45)), acting on both sides of the pick point the following equation can be found:
F c
R h w
1
2 sin 1 sin 2
T
(8-68)
Page 266 of 454 TOC Copyright © Dr.ir. S.A. Miedema