Design And Research Of A Low Frequency Negative Stiffness Structure Vibration Isolator

Vibration is widespread in nature and is harmful in most cases.For different frequencies of vibration,different isolation measures should be taken to isolate the impact of vibration.For high-frequency vibration,usually linear spring can be a very good vibration isolation method,but for low-frequency vibration,the traditional linear spring can not take into account the quality of the vibration isolation device and low frequency isolation of these two needs.Therefore,for low-frequency vibration,usually negative stiffness structure vibration isolator is a good method to achieve the lowfrequency vibration isolation demand without reducing the load-bearing capacity of the device.In this paper,the theoretical design,dynamic characteristics analysis and numerical analysis of the positive and negative stiffness parallel isolators were carried out.The vibration excitation test of the vibration isolator was executed to verify the feasibility of the design.Based on the improved application of positive and negative stiffness parallel vibration isolators,the piezoelectric actuator was installed in parallel with the original design of the vibration isolator,and the theoretical analysis and numerical study were carried out.(1)Design of negative stiffness structure vibration isolator.The vibration isolation principle of the vibration isolator is analyzed.The characteristics of the negative stiffness of the vibration isolator,the positive and negative stiffness parallel stiffness characteristics and the stiffness characteristic parameters are studied in detail.The design and characteristics of the damping nonlinear structure of the vibration isolator are analyzed,and the parameter optimization of the damping is analyzed and studied.(2)Analysis of dynamic characteristics of negative stiffness structure vibration isolator.The Taylor term expansion method was used to study the nonlinear term of the system equilibrium equation,and the feasibility of Taylor expansion was verified by error rate calculation.Using the harmonic balance method to analyze the dynamic equation of the equilibrium equation,obtain the response and the expression of the vibration transmission rate.Numerical simulation of Runge-Kutta numerical method using MATLAB software was carried out.(3)Experimental Study on negative stiffness structure vibration isolator.The parameters of the designed vibration isolator were set and processed.The sine sweep test and half sine shock test were carried out using the vibration table excitation.The experimental results were analyzed and analyzed,and the designed isolator can isolate low frequency excitation and have a good impact resistance.(4)Research on improvement of negative stiffness structure vibration isolator.The vibration isolator was further explored,and the piezoelectric actuator was connected to the original structure of the vibration isolator so that the system had both low frequency isolation ability and energy acquisition ability.The equilibrium equation of the system was obtained by Newton's law and Kirchhoff's law,and the nonlinear term was expanded by Taylor expansion.The multivariate method was used to analyze the equilibrium equation and obtain the response displacement and the output voltage root mean square expression.Using the MATLAB software to analyze the theoretical solution and study the influence of the system parameters on the output voltage root mean square.