Studies of Dynamic Responses of Spinning Shafts Including Rigid Body Motion Effect

• Main Authors: Wei-Fan Wang, 王偉帆
• Other Authors: Min-Yung Chang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/99546996922184207763

碩士 === 國立中興大學 === 機械工程學系所 === 98 === The objective of this thesis is to study the dynamic responses of the flexible spinning-shaft system including the rigid-body motion effect. The spinning-shaft system being considered include the rigid disk, the flexible shaft, and bearing supports which are modeled as springs and viscous dampers. To derive, the equations of motion of the spinning-shaft system. First, the kinetic energy and the strain energy of the spinning shaft, the kinetic energy of the rigid disk, and the work done by support forces of the bearings and centrifugal force of the disk are found. Then by employing the Hamilton’s principle together with the finite element method, the equations of motion of the spinning-shaft system including both the rigid-body motion and flexible deformation effects of the shaft are obtained. In the study of dynamic responses, in order to simplify the analysis, the influence of the flexible deformation of the shaft on the rigid-body motion of system is neglected. The equations of motion then can be divided into two groups corresponding to that of rigid-body motion and that of flexible motion affected by the rigid-body motion. The nonlinear equations for rigid-body motion is further simplified to linear ones for comparison. In the numerical analysis, a higher-order Runge-Kutta method is used to solve the equations of motion describing the rigid-body motion of the system. With above obtained results equations of flexible motion affected by rigid-body motion are then analyzed by the Newmark’s method. The influences of the parameters such as rotational viscous damping coefficient, the locations of bearings and the disk, and the motor’s acceleration on the dynamic responses are investigated. Comparisons are also made with those of the spinning shaft system without considering the rigid-body motion effect.