Finite Element Analysis of Impact-Induced Transverse Deformation in Rotating Beams

• Main Authors: Chih Yu Fan, 范志宇
• Other Authors: Wei Chen Hsu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/81531776513504711198

碩士 === 國立宜蘭大學 === 機械與機電工程學系碩士班 === 97 === In recent years, greater emphasis has been placed on the design of high-speed, light weight, mechanical and structure systems that undergo large translational and rotational displacements. The rotating structure systems such as blades of wind power generator, helicopter blades and the turbine of jet engines may be collided by a particle mass unexpectedly. The object of this investigation is to develop a reasonable and efficient numerical procedure of analyzing rotating structures under impact. In Timoshenko beam theory, shear deformation and rotary inertia are considered to insure better solution than Euler-Bernoulli beam theory. A simple model that consists of a rotating beam impacted transversely by a rigid mass was used. The angular velocity of the rotating beam did not change after a mass particle impacted the end of it. The finite element method is employed to derive the equations of motion. In addition to the basic Euler beam element, the Timoshenko beam element was used to demonstrate the effect of shear deformation and rotary inertia on the dynamic analysis of impact mechanical system. The jump discontinuity in the system variables as the result of impact is predicted using the generalized impulse momentum equations. Using the solution of the generalize impulse momentum equations, the equations of motion after impact can be solved. The effect of shear deformation and rotary inertia in the mechanical systems was examined. The difference between solutions by using the Timoshenko beam element and the Euler beam element is obvious. Especially when the ratio of length to diameter of the beam is lower than 10. The effect of the angular velocity of the beam on the flexural response of the rotating beam was also examined.