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

The Delft Sand, Clay & Rock Cutting Model.
Although the number of experiments of Hatamura & Chijiiwa (1977B) is limited, both the shear angles and the
total cutting forces tend to follow the wedge theory for blade angles of 75° and 90°. The direction of the total
cutting force measured is more upwards directed (negative angle) than predicted with the wedge theory for the 90°
blade. This could mean that the real mechanism is different from the wedge mechanism. The cutting forces
however match well.
2000
Total Cutting Force F t vs. Blade Angle α
Total Cutting Force F t (N)
1800
1600
1400
1200
1000
800
600
400
200
0
30 45 60 75 90 105 120 135 150
No Wedge hi=0.05 m
No Wedge hi=0.10 m
No Wedge hi=0.15 m
Experiments hi=0.05 m
Experiments hi=0.10 m
Experiments hi=0.15 m
Wedge hi=0.05 m
Wedge hi=0.10 m
Wedge hi=0.15 m
© S.A.M.
Blade Angle α (Degrees)
Figure 11-13: The total force of Hatamura & Chijiiwa (1977B) versus the calculated total force, with and
without wedge.
40
35
30
25
Force Direction Angle ψ vs. Blade Angle α
No Wedge hi=0.05 m
No Wedge hi=0.10 m
Force Direction Angle ψ (Degrees)
20
15
10
5
0
-5
-10
-15
-20
-25
-30
-35
-40
30 45 60 75 90 105 120 135 150
No Wedge hi=0.15 m
Experiments hi=0.05 m
Experiments hi=0.10 m
Experiments hi=0.15 m
Wedge hi=0.05 m
Wedge hi=0.10 m
Wedge hi=0.15 m
© S.A.M.
Blade Angle α (Degrees)
Figure 11-14: The direction of the cutting force of Hatamura & Chijiiwa (1977B) versus the calculated
force direction, with and without wedge.
Page 342 of 454 TOC Copyright © Dr.ir. S.A. Miedema