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力学与实践 ›› 2011, Vol. 33 ›› Issue (1): 86-88.doi: 10.6052/1000-0879-lxysj2010-295

• 教育研究 • 上一篇    下一篇

纯滚动圆轮静摩擦力方向的确定

姜芳,赵东   

  1. 北京林业大学工学院,北京 100083
  • 收稿日期:2010-07-12 修回日期:2011-02-13 出版日期:2011-02-15 发布日期:2011-03-03
  • 通讯作者: 姜芳 E-mail:jf0620@gmail.com

STUDY ON THE DIRECTION OF THE FRICTION FORCE OF A HOMOGENEOUS CIRCLE ROLLING WITHOUT SLIPPING

2   

  • Received:2010-07-12 Revised:2011-02-13 Online:2011-02-15 Published:2011-03-03

摘要: 给出了匀质圆轮受力偶或水平力作用在水平地面上作纯滚动时, 其静摩擦力方向的确定方 法. 只受力偶作用作纯滚动的圆轮, 其摩擦力的方向仅取决于外力偶矩的转向, 判断依据为 摩擦力在该圆轮的平面运动中起阻碍圆轮的转动和为圆轮的平移提供主动力两相对的作用. 当圆轮只受水平力作用作纯滚动时, 用刚体平面运动微分方程和动能定理两种方法对摩擦力 方向进行了推导判定, 摩擦力的方向不仅与水平力的作用位置相关, 还与圆轮的大小和相对 质心的惯性半径等因素相关.

关键词: 圆轮,力偶,水平力,纯滚动,静摩擦力方向

Abstract: The direction of the friction force is determined when a homogeneous circle rolls without slipping on horizontal plane under the action of the couple or the horizontal force. Only by the couple made pure rolling circle, fraction is the only force causing the linear acceleration and has a moment about the mass center whose direction is reversed to of the couple. Then, the fraction force also decreasing the angular acceleration. When the circle is acted only upon by a horizontal force, using rigid planar differential equations of motion and theorem of kinetic energy, the direction of fraction force is determined by the acting location, the radius of the cylinder and radius of gyration.

Key words: circle, couple, horizontal force, Pure rolling, direction of the fraction force