This work deals with super-harmonic responses and the stabilities of a gear transmission system of a high-speed train under the stick-slip oscillation of the wheel-set.The dynamic model of the system is developed with...This work deals with super-harmonic responses and the stabilities of a gear transmission system of a high-speed train under the stick-slip oscillation of the wheel-set.The dynamic model of the system is developed with consideration on the factors including the time-varying system stiffness,the transmission error,the tooth backlash and the self-excited excitation of the wheel-set.The frequency-response equation of the system at super-harmonic resonance is obtained by the multiple scales method,and the stabilities of the system are analyzed using the perturbation theory.Complex nonlinear behaviors of the system including multi-valued solutions,jump phenomenon,hardening stiffness are found.The effects of the equivalent damping and the loads of the system under the stick-slip oscillation are analyzed.It shows that the change of the load can obviously influence the resonance frequency of the system and have little effect on the steady-state response amplitude of the system.The damping of the system has a negative effect,opposite to the load.The synthetic damping of the system composed of meshing damping and equivalent damping may be less than zero when the wheel-set has a large slippage,and the system loses its stability owing to the Hopf bifurcation.Analytical results are validated by numerical simulations.展开更多
This paper sums up the research situation. At the influence of friction, a simulator exists the phenomenon of low-speed stick-slip. The character of low-speed of simulator is affected seriously. According to the phase...This paper sums up the research situation. At the influence of friction, a simulator exists the phenomenon of low-speed stick-slip. The character of low-speed of simulator is affected seriously. According to the phase plane method, algebra analyzing method and Lyapunov theory, the paper gives a criterion about overcoming low-speed stick-slip. Making use of the criterion, we can conclude the relationship between system parameters and low-speed stick-slip, and determine the condition where the parameters of PID controller should satisfy, for the purpose of overcoming low-speed stick-slip and has not the phenomenon of low-speed stick-slip. This method is simple and easy to carry out and the experiments show that the condition is correct.展开更多
为了研究复杂温压场下钻柱系统动力学特性,综合考虑了钻头-岩石相互作用,温度和压力对钻井液性能影响、温度对钻柱几何尺寸与特性影响以及钻柱系统所受轴向与扭转方向耦合振动,基于状态依赖时滞方法建立了4自由度直井钻柱系统动力学模型...为了研究复杂温压场下钻柱系统动力学特性,综合考虑了钻头-岩石相互作用,温度和压力对钻井液性能影响、温度对钻柱几何尺寸与特性影响以及钻柱系统所受轴向与扭转方向耦合振动,基于状态依赖时滞方法建立了4自由度直井钻柱系统动力学模型,分析了钻压(weight on bit,WOB)、驱动转速、钻井液密度以及地温梯度对系统动力学特性的影响。在此基础上,探究了WOB和驱动转速,钻井液密度和地温梯度对钻柱系统最小速度的影响规律。研究结果表明:增大钻压与钻井液密度会加剧钻柱系统振动程度,造成钻头黏滑振动;增加转速可以抑制黏滑振动;随着地温梯度的增加,会使钻头跳钻问题与黏滑振动更为严重;合理选择钻压与驱动转速能够避免黏滑振动,提高钻进效率;钻井液密度与地温梯度对钻柱系统的影响使得其最小速度呈现出一种非线性、无明显规律的特征,需要根据现场工况,结合模型进行参数优选。展开更多
基金Project(U1234208)supported by the National Natural Science Foundation of ChinaProject(2016YFB1200401)supported by the National Key Research and Development Program of China
文摘This work deals with super-harmonic responses and the stabilities of a gear transmission system of a high-speed train under the stick-slip oscillation of the wheel-set.The dynamic model of the system is developed with consideration on the factors including the time-varying system stiffness,the transmission error,the tooth backlash and the self-excited excitation of the wheel-set.The frequency-response equation of the system at super-harmonic resonance is obtained by the multiple scales method,and the stabilities of the system are analyzed using the perturbation theory.Complex nonlinear behaviors of the system including multi-valued solutions,jump phenomenon,hardening stiffness are found.The effects of the equivalent damping and the loads of the system under the stick-slip oscillation are analyzed.It shows that the change of the load can obviously influence the resonance frequency of the system and have little effect on the steady-state response amplitude of the system.The damping of the system has a negative effect,opposite to the load.The synthetic damping of the system composed of meshing damping and equivalent damping may be less than zero when the wheel-set has a large slippage,and the system loses its stability owing to the Hopf bifurcation.Analytical results are validated by numerical simulations.
基金This project was supported by the National Fund of Defense Pre research.
文摘This paper sums up the research situation. At the influence of friction, a simulator exists the phenomenon of low-speed stick-slip. The character of low-speed of simulator is affected seriously. According to the phase plane method, algebra analyzing method and Lyapunov theory, the paper gives a criterion about overcoming low-speed stick-slip. Making use of the criterion, we can conclude the relationship between system parameters and low-speed stick-slip, and determine the condition where the parameters of PID controller should satisfy, for the purpose of overcoming low-speed stick-slip and has not the phenomenon of low-speed stick-slip. This method is simple and easy to carry out and the experiments show that the condition is correct.
文摘为了研究复杂温压场下钻柱系统动力学特性,综合考虑了钻头-岩石相互作用,温度和压力对钻井液性能影响、温度对钻柱几何尺寸与特性影响以及钻柱系统所受轴向与扭转方向耦合振动,基于状态依赖时滞方法建立了4自由度直井钻柱系统动力学模型,分析了钻压(weight on bit,WOB)、驱动转速、钻井液密度以及地温梯度对系统动力学特性的影响。在此基础上,探究了WOB和驱动转速,钻井液密度和地温梯度对钻柱系统最小速度的影响规律。研究结果表明:增大钻压与钻井液密度会加剧钻柱系统振动程度,造成钻头黏滑振动;增加转速可以抑制黏滑振动;随着地温梯度的增加,会使钻头跳钻问题与黏滑振动更为严重;合理选择钻压与驱动转速能够避免黏滑振动,提高钻进效率;钻井液密度与地温梯度对钻柱系统的影响使得其最小速度呈现出一种非线性、无明显规律的特征,需要根据现场工况,结合模型进行参数优选。
