Research On The Key Techniques For The Three Arrays Of Seismic Simulation Shaking Table

Seismic simulation shaking table can accurately reflect the seismic process and carry out artificial seismic wave experiment.In the laboratory,it is the most direct and effective way to study the structural seismic and failure mechanism.With the increasing complexity of the environmental variables in the actual engineering test,the study of the vibration control strategy is becoming more and more in-depth.Especially in the seismic research of large-scale structures,the shaking table size can not be made too large,a single seismic simulation shaking table can not meet the requirements gradually,and the multiple arrays formed by the combination of multiple vibration tables are more flexible and suitable.According to the design index,the mechanical structure of three arrays of seismic simulation shaking table is designed,and complete the design of virtual prototype.Through the kinematic simulation analysis of the virtual prototype,the motion characteristics of the vibration table and the output torque and acceleration characteristics of the transmission system are obtained.Using finite element analysis method,the static analysis of the key components is carried out.Modal analysis is carried out to obtain the natural frequency and vibration mode of the structure,and the dynamic performance of the structure is evaluated.To complete a large multiple shaking table,the cooperative movement of each shaking table is the primary problem to solve.This paper is based on the combination of three earthquake simulation shaking table,the real-time high performance servo control system is designed based on the ultra high speed Ethernet EtherCAT technology,and the scheme of design of software and hardware is given.Using a master device and six device of the network structure to control three shaking table synchronization motion,and finally achieve the purpose of the three shaking table's position synchronization,speed synchronization,and acceleration synchronization.It shows that the EtherCAT servo control system has excellent control of the servo motor in the process of dealing with high density real time data,and Multi-axis network control based on bus can effectively solve the problem of multiple servo motor parallel real-time control.