fixed axle meaning in English

固定铀
固定轴

By means of the analysis on motion equation of simple pendulum , a method for testing the moment of inertia of a complex shaped rigid - body moving around a fixed axle under the condition of not knowing the barycentric position of the object was obtained
摘要通过对单摆运动方程的分析，得到了未知物体质心位置条件下测试复杂形状刚体绕定轴转动惯量的方法。