Research On Transient Dynamics Of Ultrasonic Horn

The rigid and friable materials such as porcelain are very difficult to be processed by the traditional turning or milling, therefore the ultrasonic machining came into use. How to improve the accuracy and the efficiency of the ultrasonic machining and enlarge the field of applications, reveal the mechanism of ultrasonic had been the highlight researching program. The present thesis took the ultrasonic machining as background, researched the transient dynamical response of collisions between the ultrasonic horn and workpiece, and provided the foundational theory to the optimal design of the ultrasonic machining.Based on the actual working mode, this thesis constructed the mechanical model with the influence of loaded workpiece, solved it by expanding its eigenfunctions, and realized the transient dynamical analyses. According to the method, the stepped horn and composite horn which are widely used in the engineering field were investigated in this thesis.The numerical results of a 3-section stepped horn simulated the transient response by controlling the precision in calculation scientifically. The influences of the frequency of impulses on dynamical performance of ultrasonic machining system and the effectiveness of shaped charge with loaded workpiece were analyzed.And then the transient dynamical performance of composite horn was analyzed by expanding its eigenfunctions, the discriminant for the composite horn which can be analyzed by using the formulae issued by this thesis was given. Based on Matlab, an example which described a tapered composite horn was illustrated to show its different performances under low-frequency, high-frequency and resonance-frequency impulses. By contrasting the distribution of stress both in stepped horn and composite horn, and the differences of amplifying rate, this thesis showed the different properties of composite horn and stepped horn.This thesis analyzed the transient performance of ultrasonic horn, revealed the factors that affect the quality of ultrasonic machining, and would provide the theoretical proofs for designing the ultrasonic fine machining system.