| 1. | To answer this question, we need to plot trajectories of principal stresses .
为了回答这个问题，我们尚须画出主应力迹线图。 |
| 2. | The network of lines now conforms closely with a regular system of stress trajectories .
这些线所形成的网络与规则的主应力迹线族密切吻合。 |
| 3. | Thus the directions that emerge for extremizing the normal stress are the directions corresponding to the principal stresses .
因此，产生最大正应力的方向就是相应于主应力的方向。 |
| 4. | An apparent or pseudo change in the sign occurs when a stress trajectory passes through an isotropic point .
当一个主应力迹线通过一个各向同性点时，该符号会发生一个表面上的或虚假的改变。 |
| 5. | The orientation of the principal stresses relative to the directions of the polarizer and first quarter-wave plate is of course immaterial .
主应力相对于起偏镜和第一个四分之波片方向的方位，当然是无关紧要的。 |
| 6. | The directions can be obtained by removing the quarter-wave plate and following the procedure for plane polarized light or by interpolation .
可将四分之一波片卸去，并按平面偏振光法或内插法来决定其主应力方向。 |
| 7. | Major intermediate , minor principal stress
最大中最小主应力 |
| 8. | Strength criterion of rock and effect of medium principal stress
岩石的强度准则及中间主应力的影响 |
| 9. | Maximum principal effective stress
最大有效主应力 |
| 10. | Minimum principal effective stress
最小有效主应力 |
