Dynamic Analysis Of Continuous Ultrasonic Consolidation Piezoelectric Vibration System Of Metal Foil

Ultrasonic consolidation metal additive manufacturing technology,with its advantages of low temperature,green and high efficiency,has a good application prospect in aerospace,medical instruments,ships and vehicles and other fields,and has a significant impact on the innovation of manufacturi ng industry at home and abroad.Unlike metal society with the methods of laser sintering and energy into a product,ultrasonic consolidation through friction and limited heating,produce plastic flow between metal foil,and achieve the combination of atoms.It can weld the same or different metal foils efficiently,and can embed optical fiber or other materials between the metal foils to prepare metal matrix compositesDeveloped countries have combined ultrasonic consolidation equipment with numerically controlled machine tools to achieve large-area three-dimensional metal consolidation,while domestically,foreign ultrasonic consolidation equipment is currently used to conduct research on consolidation processes.When the metal foil is continuously consolidated,due to the consolidation vibration system—the ultrasonic piezoelectric vibrator and the metal foil transmission anvil plate are two different systems,the two systems are controlled by different motors,which will cause the consolidation and conveying to be out of synchronization.Once the dual system is out of synchronization during continuous conso lidation,it will cause scratches on the surface of the welding head and the metal foil,resulting in failure of the consolidation,and even failure of the metal foil attached to the consolidation welding head and the overall damage of the equipment.This paper aims to solve the problem that the two systems are not synchronized in the ultrasonic consolidation system.A new type of consolidation equipment,push-pull longitudinal torsional composite piezoelectric vibrator,was proposed to realize the integration of consolidation and transmission functions.The main research contents of this paper are as follows:Based on the introduction of the current continuous fixed equipment working flow,the reason of machining failure was analyzed.It is concluded that the main reason of the work piece scratch is that the multi motor which is difficult to synchronize.In view of this phenomenon,a push-pull ultrasonic piezoelectric vibrator with integrated function was proposed,which avoided such problems by time-sharing multiplexing.The transfer matrix method with the fastest calculation speed was selected to establish the analytical model of push-pull composite piezoelectric vibrator.The resonant frequency was taken as the main design objective,and the structural parameters of the piezoelectric vibrator were preliminarily determined,and the analysis of the electromechanical coupling dynamics of piezoelectric vibrator was supported.Based on the principle of ultrasonic propagation and vibration theory,the structure optimization of two kinds of coupling modes,inclined groove type and train hole type,was carried out,and the finite element model of longitudinal torsional composite piezoelectric vibrator was established.The influence of key structural parameters of c ouplers on the frequency and amplitude of longitudinal torsional piezoelectric vibrator was studied,and the design criteria of the modal coupler were summarized.The dynamic analysis of piezoelectric vibrator was carried out by ANSYS finite element analys is software,and the resonance frequency,mode and amplitude curve were obtained.The advantages and application fields of the two methods were analyzed by comparing the transfer matrix modeling methods.In order to verify the feasibility and validity of t he model,the prototype was made,and the impedance analysis test,Doppler vibration measurement test and mechanical performance test were carried out.The experimental results show that the dynamic characteristics of piezoelectric vibrator are close to the simulation results,and the relative error of resonance frequency is less than 5%.The validity of the model was verified.Both sides of the piezoelectric vibrator can drive the rotor to rotate at the same time,and the maximum speed can reach 3.6 r/s,which verifies the feasibility of the proposed scheme.