The Research On Dynamic Characteristics Of Tower Equipment With Elastic Support And Damping Connection

Petrochemical high-rise tower with external frame is widely used in modern industry.It is difficult for the tower and side frame to work together under wind load,seismic load and other external dynamic loads.In practical engineering,viscous damper is used to connect side frame and tower structure to reduce external dynamic action.In this paper,the composite structure is simplified as elastic support and damped connection tower equipment.Through the theoretical study of the dynamic characteristics of this kind of structure,the basis for practical application is provided.In this paper,based on the transverse vibration theory of Euler-Bernoulli beams with equal cross-section,the transfer matrix method is used to obtain the expressions of vibration frequencies and modes of tall tower structures with elastic braces and damped connections.The method is solved by Mathematica and compared with literature to verify the correctness of this method.A fast method for calculating natural frequencies and modes of tall tower structures with elastic braces and damped connections is presented.The effects of different support conditions on the natural vibration characteristics of composite structures are studied.The modal parameters curves under different support conditions are obtained.The natural frequencies,damping ratios and mode shapes of the stiffness and damping connection towers under different support positions are analyzed.Under the rigid support,the critical damping modes of the structural system are different because of the different support positions.The influence of the support stiffness and support position on the structural frequency under the same damping connection is discussed.Under different support stiffness,the optimal support position corresponding to the highest structural frequency is different.The influence of the damping coefficient and support position on the structural natural frequency under the same support stiffness is analyzed.The optimal damping parameter table is drawn,which provides a theoretical basis for the selection of damping parameters and the design of frame stiffness in practical engineering.By comparing the experimental results of dynamic characteristics of frame towers with the calculation results of linear elastic braced towers,it is found that the second-order frequency of braced towers can not be solved when linear elastic braces are used instead of side frames,which indicates that the effect of linear elastic braces is different from that of actual braces.In this paper,polynomial approximation is used to obtain the accurate parameters of the frame acting on the tower bracing.The comparison of frequency and mode shapes shows that the parameters of the non-linear elastic bracing are accurate.Finally,the influence of non-linear damping on the dynamic characteristics of structures is studied.