Vibrations of Spatially Curved and Twisted Beams by Using Finite Element Method

• Main Authors: Lee, Yuan-Yu, 李元煜
• Other Authors: Yaw-Dong Shih
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/77616875565727874403

碩士 === 大同工學院 === 機械工程學系 === 84 === In the thesis, the governing equations for the spatially curved and twistedbeam are derived in terms of the displacement functions of three translationaland three rotation degrees of freedom. The equilibrium equation and the linearstrain- displacement relations are employed to establish the system of linear partial differential equations for the spatially curved and twisted beam. The time-independence of the displacement functions are assumed in the exponentialform. The systems of linear partial differential equations are thus reduced to be ordinary equations of eigenvalue problem for vibration frequencies. Consi-dering the restriction of boundary condition, a galerkin finite-element methodis used to solve the governing equations for the computation of the natural frequencies. The effects of the torsion and curvature which are in the geome- trically permissible region on the natural frequencies of the spatially curvedand twisted beams are studied. The result shows that the natural frequencies of the curved and twisted beam increase as either the value of torsion or curvature increases in general.