Nonlinear Character Analysis And Analog Circuit Design Of Damping Boring Bar

The paper is based on the nonlinear dynamics and control of half-initiative damping boring bar project with number:11172184, which belongs to national natural science foundation of China. With help of numerical simulation software MATLAB,dynamic analysis and parameter optimization of system are conducted. Circuit design of damping boring bar is conducted by MULTISIM.In the first chapter, the importance of damping boring bar in mechanical processing industry, especially in process of deep hole machining is expatiated.Theoretical research on control of chatter of damping boring bar and analog design of nonlinear dynamic system from experts at home and abroad is introduced in detail.The significance of analog circuit towards to system is made clear. Main content of paper is presented.In the second chapter, concepts such as analytic method,numerical simulation and nondimensionalization are introduced. Physical model of single degree of freedom and it’s dynamic equation of ordinary bar are established. Numerical simulation of system is established with MATLAB. The model of ordinary bar is established with SIMULINK.Amplitude frequency characteristic curve and time domain characteristic curve of ordinary bar are plotted to be prepared for comparison with bar of two degree of freedom.In the third chapter, common vibration type in machining is introduced, and the relationship between cutting parameter and dynamic cutting force is analyzed.Physical model of two degree of freedom and it’s dynamic equation of damping bar are established.Numerical simulation of system is established with MATLAB.The model of damping bar is established with SIMULINK. Time domain characteristic curve and amplitude frequency characteristic curve of damping bar are plotted to prove it’s superiority over ordinary bar in vibration control.In the fourth chapter, different cutting parameters such as cutting speed cutting depth amount of feed influence on dynamic cutting force according to cutting forceformula. Different amount of cutting parameters towards to influence on maximum of amplitude of damping boring bar which contributes to choice of cutting parameters in actual machining.amplitude frequency characteristic curves of damping bar are plotted. The relationship between time-domain characteristic and weight of boring bar,weight of damping block,elastic coefficient and damping are analyzed to optimize coefficients of system.In the fifth chapter, the definitions and means of plotting of phase plane and poincare section are introduced.Through combination among phase plane and poincare section in different excitation frequency, nonlinear characteristic is obtained.In the sixth chapter, the idea of modular design is presented. Integral operation and addition subtraction operation module in SIMULINK model are replaced by corresponding module. Combination of modules drafts circuit principle diagram.Through debugging and simulation, phase space plotted by MULTISIM is fit to simulation plotted by MATLAB. Based on simulation, design of circuit principle diagram is completed.In the seventh chapter, main work of research and research products are introduced. Future research work is prospected at the same time.