The Motion Analysis Of Friction Pendulum And Friction Self-excited Vibration Control Technology Research

This article studied the friction self-excited vibration, using a typical studied friction self-excited vibration experiment device friction pendulum do the experiment. First determine the friction torque when friction pendulum is working, rely on this friction torque values, using the MATLAB software to calculate the friction pendulum motion differential equation and fitting out the relationship between friction torque and friction pendulum angular velocity curve, using the ADAMS to simulation the friction pendulum’s movement, the simulation results are consistent with the results of theoretical analysis.Theoretical analysis showed that first the friction pendulum movement shows a period of decline, finally will do stable vibration in certain Angle range. From the damping characteristics of friction pendulum, found that the system is always the main body of energy consumption, and it not only change the vibration body’s initial equilibrium position but also can produce a lot of energy is damping, referred to it as the "friction damping associated". This concept "friction damping associated" is put forward by my mentor professor Gao Zhongyong, it is more reasonable to reveal the friction self-excited vibration’s mechanism of formation. Many predecessors using negative damping theory to explain the phenomena of the friction self-excited vibration, negative damping theory had far-reaching influence on the academic circles, but it’s actually not the case. In the past some research are not see friction system as a whole, the conclusion is only derived from the perspective of mathematical calculation, and ignore the difference between static and dynamic friction effect to the self-excited vibration system.Therefore in order to verify the correctness of the theoretical analysis results, uses the dynamic strain measurement system analysis and measure the vibration characteristics of friction pendulum, a series of improvement on the previous experiment, the measured friction pendulum movement cycle number increases, the measuring results of the analysis of dynamic strain measurement system reflected on the friction pendulum angular displacement, the dynamic strain measurement analysis system is real time reflecting the relation between the friction pendulum movement angular displacement and strain. output the friction pendulum friction pendulum angular displacement response curve and dynamic strain curve, Draw the curve of each parameter according to the experimental data, thus to analyze the mechanism of self-excited vibration and self-excited vibration properties of friction pendulum.Through analysis it turn out that in the friction force(torque) expression of friction self-excited vibration, friction force(torque) is influenced by the velocity item, also influenced by its acceleration, also found that the acceleration relative to the speed has a more significant influence on self-excited vibration characteristics. Maintain self-excited vibration friction force(torque), by the constant and the variables which related to the relative velocity and relative acceleration of two parts, the constant part whichconsumption external energy of the system to provide the friction associated damping,such an interpretation is more reasonable.