Abstract：Within the BTA deep-hole processing system for the turbine rotor manufacturing, since the ratio of length to diameter of drilling bar could be up to 180, and it is involved in the cutting fluid which flows rotationally and reversely for each other inside and outside of the bar, the rotational fluid-solid coupling effect on the motion stability of the flex drilling bar and on the variation and evolution of the systemic kinetics behavior is noteworthy. It was proposed for a transverse vibration model with one degree of freedom and dynamic perturbation boundaries for BTA deep-hole processing system, by means of the transformation from the dynamic contact between the precession drill cutting system and the inner-hole wall on the workpiece into a physical boundary perturbation model. Under different frequency ratio, the investigation base no the Poincare map and bifurcation was carried out by the model simulation on the effect of different systemic parameters and fluid parameters on the nonlinear dynamic behavior. The results indicated that, with the low speed rate of cutting fluid, the systemic motion situation completely exhibited the various periodical vibration and chaotic vibration under the symmetric system; and in case of the notable perturbation in the cutting fluid, especially in case of the remarkable axial pressure, the systemic cutting obviously got stable and the chaos became weak. The analytical conclusions revealed the mechanism of the effect of the fluid on the transverse vibration in nonlinear system on BTA processing, and provided helpful guidance to the optimization of the BTA deep hole processing parameters and control of the vibration.

Keyword：deep-hole processing system;transverse vibration;Poincare map;frequency ratio;bifurcation;