柔性梁线接触碰撞的动力学建模和实验研究

DYNAMIC MODELING AND EXPERIMENT TECHNIQUE FOR A FLEXIBLE BEAM WITH CYLINDRICAL CONTACT

研究作旋转运动的柔性梁的线接触正碰撞问题.基于Goldsmith的线接触撞击力模型,分别用基于小变形的混合坐标法和基于大变形的绝对坐标法建立了柔性梁的动力学方程,考虑了几何非线性效应.在此基础上,进一步考虑非线性阻尼项的影响,将Hunt,Crossley的阻尼模型推广到线接触问题.介绍了柔性梁线接触碰撞的实验方法.计算结果显示,在考虑阻尼的情况下,计算结果与实验结果吻合很好.比较了混合坐标法和绝对坐标法的撞击力计算结果,与实验结果对比表明,绝对坐标法更适用于大变形的撞击问题.

The cylindrical normal contact between a rotational flexible body and a fixed cylindrical groove was investigated. The impact dynamic equations were established by hybrid coordinate formulation and absolute nodal co-ordinate formulation based on Goldsmith cylindrical contact model, in which geometric nonlinearity was taken into account. Considering the non-linear damping terms, Hunt Crossley damping model was successfully developed to cylindrical contact. Experiment technique for the cylindrical normal contact was introduced. It is shown that the simulation results agree well with the experiment results in the case that the damping effect is taken into account. Furthermore, the impact force obtained by the present absolute nodal co-ordinate formulation was compared with that obtained by hybrid-coordinate formulation, in which small deformation was assumed. Comparison with the experiment results indicates that the present absolute coordinate model is more suitable for calculation of contactimpact with large deformation.