Study On Dynamics Modeling Method And Vibration Characteristics Of Metal Diaphragm Coupling Connecting Bolts

As an important connection part of rotating machinery,metal diaphragm coupling plays an important role in transmitting torque and compensating deflection.To this end,two equivalent bolt connection dynamics models are introduced and suitably improved,which are applied to the modeling and simulation of metal diaphragm couplings,with the aim of providing ideas for the modeling and simulation of coupling bolt connection structures,as well as providing some guidance for their vibration prediction.The main research contents of this thesis are as follows:Firstly,the stress distribution law between metal diaphragm contact surfaces is obtained by static analysis,and the simulation method of thin-layer cell modeling in different areas is proposed to determine the cell stiffness in different areas,and the free mode test is conducted with the metal diaphragm assembly as the test object to verify the correctness of the thin-layer cell modeling method in different areas.Then,a simplified model of the dynamics of two metal diaphragm coupling bond surfaces is proposed based on the virtual material method,and the virtual material parameters are obtained by Hertzian contact theory and geometric fractal theory,and the parameters are assigned to the finite element model of the metal diaphragm assembly,and the feasibility of the virtual material method modeling is verified by comparing with the modal test data and finding the model with higher accuracy;then,the verification of the vibration transmission of the metal diaphragm coupling is carried out based on the model with higher accuracy.The data show that the average deviation between the test and simulation of the origin impedance curve is within 5%,the deviation of the frequency corresponding to the main peak of the curve is within 3%,the vibration level dropout curve is in good agreement at low frequencies,and the overall trend of the curve at middle and high frequencies is consistent,which indicates that the method can be used to characterize the vibration transmission characteristics of the assembly.Second,by means of finite element analysis of the metal diaphragm structure parameters on the coupling axial and radial inherent characteristics and vibration isolation effect of the law,the data show that: the number of diaphragms only affect the first order inherent frequency position,with the number of diaphragms increased,the machine vibration isolation effect gradually reduced;with the diaphragm thickness increases,the inherent frequency to high-frequency shift,axially the machine vibration isolation effect gradually reduced,radial almost does not affect the machine vibration reduction effect.Finally,the vibration test of the whole coupling was carried out.By analyzing the data of the axial and radial excitation of the coupling,it was concluded that the test and simulation values of the origin impedance curves were in good agreement,but the axial vibration level drop curve was only in good agreement within 70 Hz,and the radial vibration level drop curve had a certain degree of agreement in the whole test frequency band.The results obtained in this thesis for the simulation and experimental study of metal diaphragm assembly and coupling whole machine can provide reference and reference for the equivalent modeling and vibration prediction of metal coupling connecting bolts.