对刚体平面运动动力学方程∑i Miz′=(dL_(z′))/(dt)的讨论

The Discussion on the Dynamic Equation of Planar Motional Rigid Body

指出了平面运动刚体在一般情况下其质心加速度不为零,过质心轴是惯性系中平移加速轴,研究刚体绕此轴的转动要考虑惯性力及其力矩,讨论了平面运动刚体的动力学方程.结果显示:对质心轴,惯性力的力矩之和为零,动力学方程与惯性系中对固定轴的动力学方程相同;对非质心轴,惯性力的力矩之和不为零,动力学方程与惯性系中对固定轴的动力学方程不同.

It is shown that the acceleration of center of mass of planar motional rigid body is not zero in general,the axis across center of mass is a translational accelerated one ininertial frame of reference,the rotation of rigid body aroundthis axis have to consider inertial force andits moment of force.The dynamic equation of planar motional rigid body is discussed.The results show：to the axis across center of mass,the resultant moment of inertial forceis zero,the dynamic equationis the same as one tofixed axisininertial frame of reference;tothe axis no across center of mass,the resultant moment of inertial forceis not zero,the dynamic equationis different fromone to fixed axis ininertial frame of reference.