Table 11 Box-Behnken experiment design factors and levels.
From: Research on coal rock parameter calibration based on discrete element method
Encoding level | Variable factors | |||
|---|---|---|---|---|
A (normal stiffness) (N/m3) | B (tangential stiffness) (N/m3) | C (maximum normal stress) (MPa) | D (maximum tangential stress) (MPa) | |
−1 | 5.0 × 107 | 3.0 × 107 | 6.6 | 1.9 |
0 | 6.4 × 108 | 4.1 × 108 | 9.8 | 6.8 |
1 | 2.3 × 109 | 1.9 × 109 | 35 | 15 |
