Smooth dynamics of oblique impact with friction
Smooth dynamics of oblique impact with friction
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DOI：
10.1016/j.ijimpeng.2012.08.001
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发表时间：
2013
影响因子：
5.1
通讯作者：
W. Stronge
中科院分区：
文献类型：
--
作者：
W. Stronge
在硬物体之间的碰撞期间的摩擦效应可以被分析为冲量p的法向分量的连续函数;即通过将冲量的法向分量视为独立变量。在接触点C处的相对速度变化的所得表达式作为连续函数vC（p）获得。接触过程中的任何滑动都受到库仑摩擦的阻碍。在这种分析中，脉冲pf的终端法向分量分成压缩或接近的初始“周期”，随后是膨胀或恢复的“周期”。对于平面碰撞，初始滑移在碰撞终止前停止，冲量的切向分量分为初始滑移的“周期”和随后的反向滑移或粘着的“周期”。对于一般的斜平面碰撞，初始滑动可以继续在原来的方向上，否则缓慢，并在分离前停止。在初始滑动停止之后，随后或者滑动方向反转，或者在摩擦系数足够大的情况下，接触粘滞。每种滑动模式的区域被映射为初始入射角、摩擦系数和碰撞体的惯性特性的函数。该映射采用两个无量纲参数;（1）归一化初始入射角和（2）取决于配置的不平衡以及摩擦系数的参数。与这些新的影响参数，终端速度和能量耗散计算作为归一化的入射角的函数，但独立的冲击速度。此外，具体的关系之间的运动学，动力学和能量恢复系数。对于摩擦的影响机构在偏心配置，它表明，这些定义是等价的，只有当滑动是单向的。
Effects of friction during impact between hard bodies can be analysed as a continuous function of the normal component of impulse p; i.e. by considering the normal component of impulse as an independent variable. The resulting expressions for changes in relative velocity at the contact point C, are obtained as a continuous function vC(p). Any sliding during contact is opposed by Coulomb friction. In this analysis the terminal normal component of impulse pfseparates into an initial ‘period’ of compression or approach followed by a ‘period’ of expansion or restitution. For planar impact where initial slip is brought to rest before termination of impact, the tangential component of impulse separates into a ‘period’ of initial sliding and a subsequent ‘period’ of either reverse sliding or stick. For oblique planar impact in general, initial sliding can continue in the original direction or else slow and come to rest before separation. After initial sliding is brought to rest, subsequently either the direction of sliding reverses or, with a sufficiently large coefficient of friction, the contact sticks. Regions for each pattern of sliding are mapped as functions of the initial angle of incidence, the coefficient of friction and the inertia properties of the colliding bodies. This mapping employs two non-dimensional parameters; (1) a normalised initial angle of incidence and (2) a parameter which depends on the unbalance of the configuration as well as the coefficient of friction. With these new impact parameters, terminal velocities and energy dissipation are calculated as functions of the normalised angle of incidence but independent of the impact speed. Furthermore, specific relationships are obtained between the kinematic, kinetic and energetic coefficients of restitution. For frictional impact of bodies in an eccentric configuration, it is shown that these definitions are equivalent only if sliding is unidirectional.