Ultrasonic Shot Peening Was Studied Based On Power Function Horn And Index-Cone Horn

Ultrasonic horn is an important part of ultrasonic shot peening system to play the role of convergence of energy 、impedance matching and amplifying amplitude. Different types of horns are required in actual production. On the one hand, in the high-intensity ultrasound peening, amplification factor and shape factor of horn are needed to be as large as possible. On the other hand, in some cases, when the transducer radiating sound waves to the media, in order to improve the sound energy, greater radiation area is often used to improve the impedance matching between the transducer and radiation medium. In the process of ultrasonic shot peening, sometimes it is needed to increase the section size of output end-face to improve the efficiency of shot peening, because the larger output end-face can be placed more firing pins or more projectiles. So it is necessary to design a horn with larger amplification factor and a larger output end-face.This paper carried out the following research:1) A new type of horn, namely, power function-shaped composite horn was researched and designed, which can overcome the constraints of amplification factor and shape factor of single horn. By using theoretical analytical method, the power function-shaped composite horn was studied. Through theoretical calculation, the horn’s vibration frequency, magnification factor and other parameter were obtained.2) In the design of power function-shaped composite horns, the simulation values of amplitude frequency are often smaller than design values. The section sizes of the horns are greater, deviation of the results is more obvious. According to the Rayleigh modification theory, the cause of this phenomenon was analyzed theoretically. Correction formula of the resonance frequency of power function-shaped composite horn was deduced, which has certain reference significance for frequency correction of complex horn. And with the aid of ABAQUS, the modal analysis was carried out to verify the correctness of theoretical derivation.3) Index-cone composite horn with a larger output end was designed and analyzed, which has a larger output end、larger radiation sound energy and higher processing efficiency. Through theoretical calculation, this horn’s vibration frequency and magnification factor were obtained.4) In the design of index-cone composite horn with a larger output end-face, the simulation values of amplitude frequency are often smaller than design values. The section sizes of the horns are greater, deviation of the results is more obvious. According to the Rayleigh modification theory, the cause of this phenomenon was analyzed theoretically. Correction formula of the resonance frequency of index-cone composite horn with a larger output end-face was deduced, which has certain reference significance for frequency correction of complex horn. And with the aid of workbench, the modal analysis was carried out to verify the correctness of theoretical derivation.5) According to the design of the two horns,two kinds of ultrasonic shot peening treatment were designed. For the power function-shaped horn, because of the smaller output end firing pins were placed on the end face of the horn. For the index-cone composite horn with a larger output end, because of the larger output end projectiles were placed on the end face of the horn.6) The first model can be simplified to facilitate researching problem. The firing pin was simplified as the projectile, so two models can share one simulation model. With the help of LS-DYNA explicit dynamic analysis method, the projectile impacting simulation was analyzed. Because there are many factors which can influence the shot peening, the projectile velocity and incident angle and the size of the radius of the projectile were considered to influence the effect of shot peening. For each influencing factor, the influence rule of shot peening effect was obtained respectively.