对二连杆机器人手臂在水平状态下仅考虑总的动能，而忽略由于手臂挠曲变形而产生的位能变化。
For the two-bar robot arm, we focus merely the whole kinetic energy at horizontal condition, and neglect the change of potential energy due to the bending deflection of the robot arm.
因此，如果需要更多的挠曲循环，应力必须降低到相应的水平。
Therefore, as the contact needs to see more and more deflection cycles, the stress level must be reduced to allow this to happen.
水平井套管柱的挠曲变形，不仅受自重引起的横向均布载荷的影响，而且还受轴向力的影响，同时还可能有初弯曲。
The flexual deformation of casing in a horizontal hole is caused not only by the uniform transverse load from dead weight, but also by the axial load, and the existence of initial bent if any.
应用推荐