复合材料镗杆高速切削系统非线性再生颤振与稳定性

The nonlinear regenerative chatter and stability of composite boring bar (CBB) operated in high-speed deep hole are crucial problems in developments of advaced machining system. So far, no complete framework for the theoretical research on nonlinear regenerative chatter and stability of CBB cutting process has been constructed. The project is aimed at the CBB cutting system with geometric nonlinear, the research objectives are to develop the scientific method of predicting the dynamics of CBB cutting process and gain an insight into the effects of composite internal damping on the dynamic behavior of CBB cutting process. On the basis of theory for the three-dimensional nonlinear elastic anisotropic beams , nonlinear vibration theory, regenerative cutting forces and micro composite damping mechanical model, the key issues under consideration in the project are :.1. Accurate prediction of composite internal damping, chatter onset threshold (stability lobes) and nonlinear chatter responces and forced responses of CBB cutting process by means of the analytical technologies presented by the project, which includes model reducing,time/frequency methods and miro mechanical evaluation theory for composite internal damping..2.The effects of stacking sequence, miro mechanical characteristics, temperature and frequency as well as constrained layer damping on the nonlinear dynamic behaviours and chatter stability of CBB cutting process..The project will present scientific characterizations and evaluation techniques for the nonlinear regenerative chatter and stabilizing mechanism, in order to serve as the basis for the future machining dynamic stability design and nonlinear regenerative chatter control of CBB cutting process.

复合材料镗杆（CBB）切削系统在深孔高速加工中的非线性再生颤振与稳定性是发展先进机床切削系统亟待解决的问题。迄今为止，国内外尚未就CBB切削系统非线性再生颤振和稳定性机理，提出完整的理论研究体系。本项目拟针对几何非线性CBB切削系统，以建立科学的CBB切削系统动力学分析方法，揭示复合材料内阻对CBB切削系统动力行为的影响为目标，以复合材料梁非线性理论、再生切削力理论、非线性振动理论和细观阻尼理论等学科方法为指导，重点就CBB切削系统复合材料内阻、稳定性极限、非线性颤振响应、受迫响应建模和模型缩聚技术、时/频域算法、复合材料内阻细观估计原理，以及叠层方式、温度、频率和约束层阻尼等因素对CBB切削系统非线性动力行为与颤振稳定性的影响，进行系统的研究；针对CBB切削系统非线性颤振稳定性理论体系，提出科学完整表征方法与评价技术，为最终实现CBB切削系统动力稳定设计与非线性再生颤振控制，奠定基础。

复合材料刀杆（CCB）切削过程再生颤振和稳定性及其非线性动力学行为，是发展先进机床切削系统亟待解决的问题。本项目采用变分渐进复合材料梁理论和拉格朗日方程，导出拉-弯-弯-扭耦合CCB切削系统再生颤振稳定性分析模型。基于粘弹性Kelvin-Voigt应力应变本构关系和能量法建立CCB内阻模型。基于Rayleigh轴理论、Hamilton原理，提出考虑CCB内、外阻的切削系统再生颤振稳定性分析模型。基于Euler-Bernoulli梁理论和复刚度法提出约束层阻尼CCB切削系统再生颤振稳定性分析模型。基于高阶变形理论，建立CCB再生颤振非线性动力模型。基于不可伸长假设，建立考虑CCB曲率和惯性非线性以及内、外阻的再生颤振非线性动力模型。采用Galerkin法和改进的Adomian分解法进行模型降阶。采用频域特征值法计算临界转速和失稳阈。采用频域法、时域半离散法结合时间响应数值积分法，计算稳定性叶瓣曲线。采用多尺度法和时间积分法研究切削系统的非线性动力学，构造主共振和超谐共振响应摄动解。揭示CCB剪切变形、铺层方式、长径比、锥度比、外阻、内阻、阻尼层和约束层厚度，以及CCB旋转速度和切削力参数对切削稳定性和受迫振动的影响。研究发现，外阻抑制切削颤振；而内阻的作用具有两面性，在亚临界区，它抑制切削颤振；在超临界区，它诱发颤振，出现新的不稳定区域，不稳定区域的启动速度等于旋转CCB的失稳阈。铺层方式、长径比和锥度比影响CCB内阻，从而影响切削系统的稳定性。忽略CCB的剪切变形，将会过高估计切削稳定性。对于再生颤振非线性切削系统，激励正/反进动涡动模态仅能产生正/反进动模态的主共振和超谐共振响应。具有曲率和惯性非线性或者高阶变形非线性的CCB切削系统的等效非线性为Duffing类硬弹簧非线性，共振响应出现多值性和跳跃性。非线性切削系统的等效阻尼由内阻、外阻和再生颤振阻尼构成，后者与转速成反比。正进动模态的等效阻尼总是小于反进动模态的等效阻尼。因此，正进动模态非线性受迫响应幅值总是大于反进动模态非线性受迫响应幅值。上述研究成果为CCB切削系统的颤振稳定性以及非线性动力学控制，奠定基础。