Direction: In an orthogonal machining operation:
Uncut thickness = 0.5 mm
Cutting speed = 20 m/min
Rake angle = 15°
Width of cut = 5 mm
Chip thickness = 0.7 mm
Thrust force = 200 N
Cutting force = 1200 N
Assume Merchants theory.
-
The values of shear angle and shear strain, respectively, are
-
- 30.3° and 1.98
- 30.3° and 4.23
- 40.2° and 2.97
- 40.2° and 1.65
Correct Option: D
Here, r = cutting ratio,
| n = | = | = 0.714 | ||
| t2 | 0.7 |
| ∴ tanφ = | |
| 1 − rsinα |
where, φ = shear angle
and α = rake angle
∴ φ = 40.2º
Shear strain = cot φ + tan (φ – α) = 1.65
