Dynamic Modeling And Structural Design Of Piezoelectric Vibrator System For Ultrasonic Consolidation In Ultrasonic Additive Manufacturing

Ultrasonic additive manufacturing technology is a new method to realize low cost and green manufacturing of advanced materials and structures,based on laminated object manufacturing.Under the action of high-frequency vibration and static pressure,the high-performance structure is realized by the layer-by-layer method to achieve solid metallurgical bonding between metal foils.The piezoelectric is the core component to generate vibration and realize energy conversion in UAM equipment.In the process of welding,the piezoelectric vibration is under complex boundary conditions and involves mechanical clamping and friction.Thus it has a significant impact on the dynamic characteristics of the system and direct impact on the performance of the material after cementing.Efficient and accurate dynamic analysis method is the key to realize the optimization design of piezoelectric vibrator structure.This paper focuses on the piezoelectric vibrator in UMA equipment,specific research content are as follows:1.Outlines the principle of metal material manufacturing technology and its increasing classification.Then discusses the advantages and development trend of UAM.Detail the principle of ultrasonic fixation technology.Finally,focusing on the the core component of the ultrasonic fixation equipment--piezoelectric vibrator,puts forward the main research question of this article.2.Introduces the modeling method of piezoelectric vibrator,by comparing the characteristics of several common dynamic modeling method.Then discusses the advantages of the transfer matrix method in establishing the dynamic coupling model of piezoelectric vibrator.Furthermore,derives the method and procedure of establishing dynamic coupling model by transfer matrix method.3.Establish the dynamic coupling model of piezoelectric vibrator bases on transfer matrix method.Then uses Matlab to solve the transfer matrix dynamics model.Finally,the dynamic response results of resonant frequency,speed ratio,mode and maximum output amplitude are obtained.4.Uses Ansys to establish the finite element model of the same piezoelectric vibrator.Under the same boundary conditions and the electric excitation,respectively using two kinds of method to establish dynamic model for the simulation calculation,the model is validated by comparing and analyzing of calculation results.The relative error of the resonant frequency,speed ratio,and welding head maximum amplitude of vibration calculated by the two models are 2.8%,3.9% and 6.7% respectively.The effectiveness of the transfer matrix method to establish a dynamic coupling model has been verified.5.Using the established transfer matrix model to optimize the structure parameters of the piezoelectric vibrator.First,introduces the specific train of thought to optimize the size of piezoelectric vibrator structure using transfer matrix model.and then through the optimization idea to the resonance frequency of the piezoelectric vibrator structure(20 kHz)as the design goal to optimization analysis of the structure size.By adjusting the structure size,the resonant frequency of the piezoelectric vibrator decreased from 20.9kHz to 20.04 kHz..In addition,this paper discusses the electric excitation matching way of this type piezoelectric vibration subsystem of two symmetrical distribution of half wave transducer.Through the above works,this paper established a dynamic coupling model of piezoelectric vibrator structure of UAM,and put forward the method and step to make use of the model for further study in designed new type piezoelectric stator structure foundation...