本文主要探討含內部黏滯阻尼之Timoshenko樑的自由與強迫振動特性。沿用Clough及Penzien對黏滯阻尼的定義,利用能量法推導出具內部黏滯阻尼之Timoshenko樑的運動方程式,再利用傳遞矩陣法(Transfer Matrix Method)求得系統具有局部均勻分佈阻尼時之系統特性。由數值計算的結果可以得知,當局部阻尼值持續增加時,阻尼段部份的特性會趨近於剛體的特性,失去阻尼消散能量的性質。利用本文所提出之方法可得當阻尼持續增加時,阻尼效應的臨界點及其現象。
In this study, based on conceive of Meirovitch and Clough, the equation of motion of the Timoshenko beam with the internal viscous damping is derived. Using the Transfer Matrix Method, the natural frequencies and the mode shapes of the system are determined. The cases of the beam with local internal viscous damping are also calculated. Finally, from the numerical calculation, when the locally distributed damping increases, the property of the damp section will turn into the property of rigid body. By the present method, the critical property can be found when the damping increase.