共查询到16条相似文献,搜索用时 74 毫秒
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一种刚体系统无初速释放瞬时加速度的求解方法吴亚平(兰州铁道学院,兰州730070)1基本方法对于具有完整,理想约束的非自由质点系,D'Alembert-Lagrange原理可表为以下形式设系统有k个自由度,则各点矢径r_i,可用k个广义坐标q_1,q... 相似文献
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一般运动刚体的恢复系数公式的适用条件 总被引:1,自引:0,他引:1
一般文献中,当用到关于恢复系数的牛顿公式时,都是针对两体碰撞的.该文针对两个受到一定外力作一般运动的刚体之间的碰撞,导出了牛顿恢复系数公式的适用条件. 相似文献
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空间运动刚体的加速度投影定理王允地,侯东生(西北轻工业学院机械系,咸阳712081)1定理的提出作空间一般运动的刚体,其上任意两点的速度在两点连线上投影相等,这就是众所周知的速度投影定理。但两点加速度在两点连线上投影的关系如何,同样是一个值得研究的问... 相似文献
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????? ??? ???? 《力学与实践》2008,30(5):98-98
通过向量运算给出了角速度向量引入的一种较简单的方法. 利用刚体上的固连向量的导数与
其自身垂直的特点,得出反映刚体整体运动特性的角速度向量,并对这样的导出方法与刚体
角速度向量物理意义之间的联系进行了讨论. 相似文献
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刚体平面运动学问题的复数解法 总被引:2,自引:0,他引:2
刚体平面运动学问题的复数解法金明德(南京气象学院基础科学系,南京210044)1引言在理论力学教材中,讨论刚体作平面运动的问题,总是将刚体的平面运动看成随基点的平动和绕基点转动的合成。因此,求刚体上任一点速度的方法也采用基点法(或由基点法派生的速度瞬... 相似文献
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《European Journal of Mechanics - A/Solids》2006,25(5):854-866
This paper considers the problem of optimal controlling a spacecraft programmed motion without its angular velocity measurements. An optimal control law that stabilizes this programmed motion and minimizes the cost that transfers the spacecraft from arbitrary initial state to the programmed state is obtained as a function of the kinematics attitude parameters and their estimates as well as the angle of programmed rotation. The stabilizing properties of the proposed controllers are proved using Liapunov techniques. Numerical simulation study is presented. 相似文献
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The problem of optimal transfer of a rigid body to a prescribed trajectory of preset angular motion is considered in the nonlinear statement. (The control is the vector of absolute angular velocity of the rigid body.) The functional to be minimized is a mixed integral quadratic performance criterion characterizing the general energy expenditure on the control and deviations in the state coordinates.Pontryagin’s maximum principle is used to construct the general analytic solution of the problem in question which satisfies the necessary optimality condition and ensures the asymptotically stable transfer of the rigid body to any chosen trajectory of preset angular motion. It is shown that the obtained solution also satisfies Krasovskii’s optimal stabilization theorem. 相似文献
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Yan-Zhu Liu 《Acta Mechanica Solida Sinica》1988,1(4):407-418
The phase-plane method of nonlinear oscillation is used to discuss the influence of the small dissipation upon the Euler-Poinsot motion of a rigid body about a fixed point. The equations of phase coordinates are applied instead of Eulerian equations, and the global characteristics of the motion of rigid body are analysed according to the distribution and the type of the singular points. A Chaplygin's sphere on a rough plane, a rigid body in viscous medium and one with a cavity filled with viscous fluid are discussed as examples. It is shown that the motions of rigid bodies dissipated by various physical factors have a common qualitative character. The rigid body tends to make a permanent rotation about the principal axis of the largest moment of inertia. The transitive process can change from oscillatory to aperiodic with the decrease in dissipation. 相似文献
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