Optimal Design Of Horn For Small Hole Extrusion Machining With Ultrasonic Vibration

Horn is the key component of ultrasonic machining system,and the design of dedicated horn is the premise of studying various kinds of ultrasonic machining technology.In order to meet the application requirements of small hole extrusion machining with ultrasonic vibration,an unconventional composite horn was proposed and optimized.The simulation and machining experiment results confirm the validity of the optimization method.The main contents of this thesis are as follows:(1)Several conventional horns were designed and analyzed.Based on the finite element analysis results of several conventional horns,a cylindrical-Gaussian-conical composite horn was proposed,which is more suitable for small hole extrusion machining with ultrasonic vibration.(2)Through the optimal Latin hypercube sampling method and simulation experiments,29 groups of training data and 9 groups of validation data were obtained.Based on the training data,surrogate models for predicting the performance parameters of horn were constructed by using Polynomial Response Surface method,Kriging method and Support Vector Regression method,respectively.Based on the validation data,the prediction accuracy of surrogate models were evaluated.The surrogate model constructed by Kriging method has the highest prediction accuracy.(3)Taking the structural parameters of the horn as design variables and taking the resonant frequency,amplitude amplification factor and Minimum vibration stopping force of the horn as optimization objectives,a multi-objective optimization model of the horn was established.Combining the surrogate model constructed by Kriging method with genetic algorithm,the multi-objective optimization design of horn was completed.After optimization,the simulation results show that the performance parameters of the horn achieve the design goals.(4)The optimized horn was manufactured,the experimental platform was built,and the machining experimental of bovine bone slices was carried out.The machining experimental results show that the optimized horn can meet the actual application requirements and the machining effect is ideal.