A Study on the Properties ofRotating BTA Drill Shaft
|摘要:||本論文主要是推導含中間支撐、流體與軸向壓力的旋轉BTA深孔鑽刀桿之特徵性質之研究。座標系統選擇附於BTA刀桿之旋轉座標系統，並將動態系統之能量方程式列出，然後再根據漢彌頓原理(Hamilton's Principle)推導出BTA深孔鑽刀桿之運動方程式。對於不含中間支撐旋轉BTA深孔鑽刀桿之運動方程式係根據包含剪力變形、旋轉慣性矩與陀螺儀效應之金摩辛格樑模式(Timoshenko Beam Model)與尤拉-伯努利樑模式(Euler-Bernoulli Beam Model)為之。中間支撐旋轉BTA深孔鑽刀桿之運動方程式係依據尤拉-伯努利樑模式為之。對於運動方程式之解，吾人使用蓋樂金法(Galerkin's Method)解其運動方程式以得到動態系統之特徵值。
同時，本論文也採用兩種實驗方式檢驗BTA深孔鑽刀桿之特徵值：脈衝式實驗法(Impulsive Testing)用於檢驗非旋轉深孔鑽刀桿之特徵值；另外一種是隨機輸入刺激實驗法(Random-Input Excitation Testing)用於檢驗旋轉深孔鑽刀桿之特徵值。實驗結果將與理論值比較。
The object of this investigation is to develop the equations of motion and analyze its eigenproperties of a rotating BTA drill shaft without and with intermediate support, containing flowing fluid and subject to a axial compressive force. The energy formulations were based on a co-ordinate system which is attached to the rotating BTA drill shaft (moving co-ordinate system) and the equations of motion were derived by using Hamilton's principle. This problem was studied using two models on a rotating BTA drill shaft without intermediate support: a Timoshenko beam model (which includes shear deformations, rotatory inertia moment, and gyroscopic moment effects) and a Euler-Bernoulli beam model. Also, the rotating BTA drill shaft with intermediate support was studied on a Euler-Bernoulli beam model. The Galerkin's method was utilized to obtain the eigenproperties. Two kinds of experimental testings were performed to investigate the eigenproperties of a rotating BTA drill shaft. The first one is impulsive testing for a non-rotating drill shaft, the other is random-input excitation testing for a rotating drill shaft. Also, the comparison with experimental results to examine the simulations is made in this study. Beside the study of eignproperties of the rotating BTA drill shaft, we also constructed the cutting force model of a multi-edge BTA drill head based on the orthogonal principle. The simulation values were compared with experimental results.
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