Study On The Mechanism Of Particle Damping In The Strut Of Wind Tunnel Model

The wind tunnel test system is one of the important simulation tests to check whether the performance of the aircraft is good or not,but it will inevitably produce vibration in the test process,especially the resonance phenomenon of the wind tunnel strut structure,which leads to the aircraft can not perfectly simulate the movement in the air,the measurement data obtained by the sensor is not accurate enough,and the strut fracture phenomenon occurs in serious cases,resulting in huge economic losses.At present,the active control method is widely used to suppress the vibration of the wind tunnel model strut at home and abroad,but most of the vibration suppression structures are relatively complex and high cost.Therefore,in this paper,the mechanism of vibration suppression of particle damping on wind tunnel model strut is proposed,and the combination of particle damping and nonlinear energy sink is proposed to be applied to the vibration suppression of wind tunnel model strut.The main contents of this paper are as follows:(1)firstly,the contact force between particles is analyzed,and the contact force between particles is calculated by Hertz based elastic contact theory.Combined with gas-solid two-phase flow theory,the equivalent viscous damping and Coulomb friction damping caused by drag force between particles are simulated.At the same time,the strut system of the wind tunnel model is simplified,and the dynamics and kinematics of the strut system are analyzed;(2)Secondly,the dynamic equation of the strut of the particle damping wind tunnel model is established,and the numerical simulation method of Runge Kutta is used to solve it.Under the condition of forced vibration and free vibration,the vibration suppression effect under different particle parameters is obtained,and the specific influence law of particle parameters on particle damping vibration suppression is explored.At the same time,the simulation results are verified in the EDEM discrete element software,and the actual wind tunnel model strut is processed based on the PLA new material by using 3D printing technology,which is verified by the real experiment.The theory and simulation are combined;(3)finally,based on the research foundation of particle damping technology,a new structure of segmented NES particle damping is designed by combining particle damping with non-linear energy well.The damping of NES is adjusted by particle damping,and the vibration absorption effect is simulated.A wind tunnel model strut system test platform is built to compare the simulation effect of segmented NES particle damping The results show that the particle damping can effectively adjust the damping of the nonlinear energy well and achieve a better vibration suppression effect.