A Timoshenko oscillator consists of an object set into motion through two opposite frictions of its rotating cylindrical supports. Coulomb’s law of friction determines that the oscillator’s motion should be simple harmonic vibration. However, experiments show that it is more like a damped vibration which is caused by non-Coulomb effects between the oscillator and two cylinders. We carefully measured the variance of kinetic frictional coefficient μ with relevant parameters and provide a brief explanation of this phenomenon. Both linear and quadratic approximation are used to derive the damped vibration equations. Moreover, numerical calculation based on interpolated data is also performed to give an accurate vibration curve. We find excellent agreement of our theory with the experimental data. A Timoshenko oscillator is an easy-to-build experiment for undergraduates to practice and understand friction. The non-Coulomb effects discussed in this article will give them a more realistic view of friction.

Timoshenko 振荡器由一个物体组成，该物体通过其旋转圆柱形支架的两个相反的摩擦力而运动。库仑摩擦定律决定了振荡器的运动应该是简谐振动。然而，实验表明它更像是由振荡器和两个圆柱体之间的非库仑效应引起的阻尼振动。我们仔细测量了动摩擦系数μ的方差相关参数，并对该现象进行简要说明。线性和二次近似都用于推导阻尼振动方程。此外，还进行了基于内插数据的数值计算，以给出准确的振动曲线。我们发现我们的理论与实验数据非常吻合。Timoshenko 振荡器是一个易于构建的实验，供本科生练习和理解摩擦。本文中讨论的非库仑效应将使他们对摩擦有更真实的看法。