Magneto-rheological vibration suppression intelligent boring bar from the theory and method

　　Title: Magneto-rheological vibration suppression intelligent boring bar from the theory and method
　　Author: Kong Tianrong
　　Degree-granting units: Zhejiang University
　　Keywords: deep hole boring;; flutter suppression;; magneto-rheological fluid material;; intelligent boring bar;; variable structure stiffness;; nonlinear stochastic optimal control;; semi-active vibration control
　　Abstract:
　　Precision Hole for common flutter, this paper combined with the National Natural Science Foundation "from the magneto-rheological fluid-based intelligent boring bar vibration suppression component theory and method" (item number: 50405036) and Zhejiang Natural Science Foundation " magneto-rheological fluid from intelligent boring bar vibration suppression component theory and method "(item number: Y104462), through theoretical analysis, numerical simulation Neodymium Magnets and experimental verification of the application of magneto-rheological techniques to suppress the process of boring issues of cutting chatter in-depth study of the system.
　　Chapter 1, describes the research background of the degree and significance of details at home and abroad for cutting chatter control technology research status, clear cutting tool chatter control technology development, presented the main research papers.
　　Chapter 2, the establishment of a Boring flutter vibration mechanics model system to study the root causes of flutter, while the spindle speed cutting method, the flutter suppression mechanism has been studied, has been the nature of its causes flutter suppression. On this basis, the structural stiffness and damping the impact of change on the stability of the system conducted in-depth study of proposed variable structure stiffness flutter suppression method, and theoretically confirmed it with variable speed cutting method has the same effect.
　　Chapter 3, based on the characteristics of magneto-rheological fluid material presented to support stiffness controllable magneto-rheological vibration suppression since the design of intelligent boring bar, and key structural vibration suppression of magneto-rheological fluid unit of the parameter optimization. ANSYS finite element simulation of the optimized structural parameters, results showed that the main performance indicators to meet the design requirements.
　　Chapter 4, the first load through the static method of intelligent boring bar of the rigidity and damping characteristics of the test, found that http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets after the boring bar in the static magnetic field flexibility and damping characteristics change significantly; second excitation method using transient and steady-state excitation method were carried out on intelligent boring bar dynamics test and analysis of intelligent boring bar of the rigidity and damping on the size of the magnetic field intensity changes of its dynamic characteristics and vibration frequency, amplitude, and the relationship between the magnetic field strength; Finally, intelligent boring bar response time for the test. Research was supported by the magneto-rheological vibration suppression intelligent boring bar from the variation of static and dynamic characteristics and modeling, will provide effective control strategy to develop its scientific basis.
　　Chapter 5 presents a model based on Kelvin and Maxwell models of magneto-rheological fluid material constitutive model, the establishment of a Euler-Bernoulli beam model based on magneto-rheological vibration suppression intelligent boring bar from the dynamic model, with consumption and with San function of intelligent boring bar Lagrange equation of the dynamic characteristics of a theoretical analysis and numerical simulation. In order to meet the requirements of real-time control, but also the introduction of Bouc-Wen model, this model was established based on kinetic model of intelligent boring bar, and the theory of nonlinear least-squares method to identify the relevant parameters, and finally the numerical simulation, The results show that it can accurately describe the dynamics of intelligent boring bar, the development of real-time control strategy for follow-up basis.
　　Chapter 6, according to the process of boring chatter Zhen, development and maturity characteristics of each stage, the whole boring process divided into two situations, and on this basis have raised a non-linear stochastic optimal semi-active control strategies and semi-active variable stiffness control strategy. For non-linear stochastic optimal semi-active control strategy, its control law was derived, also put forward the corresponding performance criteria, and for the control simulation. For semi-active variable stiffness control strategy, its control parameters optimized for the theoretical analysis and numerical simulation to do the relevant research.
　　Chapter 7, in order to verify the proposed front of the correctness of the theory and methods, established on the lathe CA6140 magnetorheological vibration suppression intelligent boring bar from the cutting chatter control experiment platform for the relevant experiments. First non-linear stochastic optimal semi-active control strategies Chatter control experiments to study the damping effect of the actual and verify the theoretical analysis results are correct. Secondly, for semi-active variable stiffness control strategy of cutting chatter suppression experiment, and verified by experimental methods to optimize the control parameters of reasonableness of the results.
　　Chapter 8 summarizes the paper's research and innovation, and prospects for future research.
　　Degree Year: 2009