Study Of Interaction Damping Of The Primary-secondary Coupled System

The dynamic interaction between the primary structure and secondary structure present in the primary-secondary coupled system is very complex. The dynamic characteristic of primary structure usually be changed by the secondary structure, and there is also energy transformation in the coupled system. In this paper, the characteristics of the dynamic interaction is studied, the absorption and distribution of energy of the coupled system are adjusted by selecting reasonable design parameters. As a result, the interaction damping system is achieved.Firstly, the series double degree of free model and dynamic equations of the coupled system are established, and the effects of the frequency ratio and mass ratio on the dynamic characteristics are analyzed. The effects of frequency ratio and mass ratio on the random seismic response of the system are studied. Besides, the interaction damping system is achieved by optimizing the mass and frequency of primary structure based on the multi-objective programming method. The results show that the frequency ratio and mass ratio cause the offset of the natural frequencies of system. The frequency ratio of system is the significant parameter affecting the response of system. The response of system is controlled effectively when the frequency ratio is 0.56 to 0.60 and the mass of primary structure is low.Secondly, the space model of the coupled system based on sub-structure assembly technology is established, and the spatial arrangement of secondary structure and the lateral-torsional coupling effect of primary structure are considered. The effects of the seismic input and the eccentricity of primary structure on the arrangement of secondary structure are investigated. Then, the arrangement of secondary structure is optimized based on the multi-objective programming method. Besides, the genetic algorithm is proposed to optimize the spatial arrangement of secondary structure. The results show that the effect of arrangement of secondary structure on its response is large, and the effect on the primary structure is small. Moreover, the effects of seismic input and the eccentric direction on the arrangement of secondary structure are large, while the effect of eccentric degree is mall. Besides, the optimal arrangement of secondary structure is inclined to the direction of the stiffness center of primary structure.Finally, the space model of the coupled system with the connection is established. The effects of the mass, frequency and damping ratio of the connection on the transfer function of the coupled system are studied. Besides, the effects of the mass and frequency on the dynamic response of the system are analyzed. The multi-objective programming method is proposed to optimize the frequency and mass of connection. The results show that the effect of frequency of connection on the response of the system is large, and the attitude is different for the different objects. The increase in the damping ratio of connection can decrease the dynamic response of the system effectively. Besides, the frequency of connection has poor robustness. The optimal design parameters of connection are selected based on the multi-objective programming method.The interaction damping analysis of the coupled system can display the dynamic interaction clearly, and provide reference significance for the seismic damping of the structures. Besides, the analysis also provides a foundation for the seismic damping of the accessory structures or electromechanical equipment in theory.