对自由大范围运动情况下刚体-柔性梁系统的刚柔耦合动力学特性进行了研究。考虑系统作平面大范围运动及柔性梁的纵向和横向变形,在纵向变形位移中计及横向弯曲引起的轴向缩短,即耦合变形项。采用假设模态法对柔性梁进行离散,运用拉格朗日方程推导出系统刚柔耦合动力学方程。分大范围运动为转动、平动,平面运动进行了动力学仿真,重点探讨了大范围平动下的刚体-柔性梁系统的刚柔耦合动力学特性。首先研究了系统在外界激励作用下的耦合动力学,其次分析了已知大范围平动对柔性梁小变形运动的影响。结果表明:零次近似模型不能反映大范围平动和柔性梁小变形运动之间的耦合作用;在不同的大范围平动加速度下,柔性梁中既可存在动力刚化效应,也可存在动力柔化效应。
The rigid-flexible coupling dynamic properties of a hub-flexible beam system undergoing free large overall plane motions are studied.The longitudinal deformation and the transverse deformation of flexible beam are considered and the coupling term of the deformation which is caused by transverse deformation is included in the expression of longitudinal deformation.The governing equations of motion for this system are established using assumed mode method and Lagrange's equations.The dynamics of the system undergoing rotation or translation or plane motion are simulated,and the emphasis is the rigid-flexible coupling dynamic properties of the system undergoing translation.The coupling dynamics of the system under external excitations is simulated firstly.And secondly the influence of translation on the small deformation motion of flexible beam is analyzed.It is shown that the traditional zero-order approximation model can not describe the coupling effect between the translation and the small deformation motion of flexible beam.Also,both phenomenon of dynamic stiffening and dynamic softening can occur in the beam when the system undergoes different acceleration of translation.