fluctuating stress的用法和样例：
例句
- In the process of dynamic unloading, the radial stress unloaded first and then rebounded, the circum stress concentrated.
初始应力动态卸荷时，动应力在隧洞径向表现为卸荷回弹，而在切向出现动应力集中，表现为加载。 - Under the action of the horse head movement, the vibration of the sucker-rod and, furthermore, thedynamic stress will be induced.
在这种悬点位移作用下，将引起抽油杆柱的振动，导致杆柱中的动应力。
