The Optimal Design And Application Of An Innovative Damping Devices Based On Equivalent Linearization Method

Earthquake leads great damage to the building structure,and a serious threat to human life and property safety.Structural vibration control technology breaks through the traditional concept of seismic design,it sets up additional control device with structure systems jointly and reduces the earthquake excitation.The structural vibration response was reduced and the seismic performance of the structure can be improved.In this paper,an innovative type of damper,also a passive control device,gyro-mass damper(GMD),is studied.Based on the damper model test results,a simulation model was established.Further,the optimal design of single degree of freedom structure with GMD was carried ou,and the comparison of damping effect was verified.The main researches in this study are presented as follows:(1)Based on the mechanism of the ball screw,the mechanism of response amplification along with mass and damping ratio are studied.It is found that the two parameters can be optimized simultaneously by adjusting the lead length of the ball screw.Based on the existing low frequency and low amplitude test data,the friction effect of GMD was analyzed and the SIMULINK model was established to identify the GMD parameters.The friction was taken into account and a corresponding simulation model was established.Finally,the GMD mechanical model combine with mass unit,damping unit and friction unit is determined.The dynamic performance of GMD is analyzed under various working conditions.(2)The friction effect of the device is ignored for the large-size GMD,generally.The structural parameters of single degree of freedom with GMD are optimized based on the fixed-point theory.When the damping ratio of single-degree-of-freedom system is zero,the optimal frequency ratio and the optimal damping ratio to mass ratio are deduced.As the mass ratio increases,the range of the resonance region relatively expands and the amplitude decreases.When the damping ratio is small,the optimization formula that ignores the friction can be used as a reference.When the damping ratio is larger,the optimal parameter value is obtained according to the numerical search method,and the optimal design curve is drawn as design reference.(3)For the GMD in which the friction effect should be taking into account,the equivalent linearization(EQL)model of GMD was proposed.Using Gaussian white noise and Kanai-Tajimi spectrum as ground motion excitation,the equivalent linearization method and SIMULINK numerical simulation results are compared.The results show that the coincidence of displacement and velocity standard deviation is good,and the coincidence of transient response displacement and velocity agreed well.The validation of the EQL model and the GMD shows that,GMD can decrease the vibration of the structure effectively.