Tiny deformation will appear in the local of the propeller shaft of certain ship which is endured an invariableness load, although the shaft stress is within the elastic limit range.

• 某舰的螺旋桨尾轴长期处在恒定载荷作用下，虽然尾轴应力在弹性极限范围内，但是尾轴局部还是很容易发生微量的塑性变形。