Equipment Design and Process Study of Ultrasonic Shot Peening
|School||Taiyuan University of Technology|
|Course||Mechanical Manufacturing and Automation|
|Keywords||Ultrasonic shot peening equipment Cascade horn Modal Analysis LS-DYNA finite element simulation Pellets impact|
Ultrasonic shot peening equipment machinery parts enhanced treatment equipment the traditional gas shot peening and shot blasting equipment replacement equipment. It is widely used in higher fatigue strength and life requirements of the mechanical parts of the aviation, aerospace, automotive, nuclear power, weapons, petroleum, coal, chemical, motorcycle, engineering machinery, turbines, agricultural machinery, plastic molds, electrical switches industrial sectors. Ultrasonic shot peening equipment consists of ultrasonic generator, transducer and horn composition, which occupies a very important position in the shot peening process horn, its main role is to input mechanical transducer at its output the particle displacement or velocity of the vibration amplifying the ultrasonic energy is concentrated in a smaller area. The amplification factor is an important performance parameters, horn ultrasonic shot peening process, the pellets speed far reach to be able to destroy the degree of stability of the spray pieces and, therefore, improve the impact velocity of the pellets that improve luffing rod amplification factor to become the primary task of the development of ultrasonic shot peening equipment, and obviously can not meet the requirements of the traditional shape of a single horn. To improve the horn amplification factor for the fundamental purpose of design theory based analytical method, cascading horn design and simulation analysis by finite element software LS-DYNA ultrasonic shot peening process. The main contents are: Analytical design of a single, composite horn by comparing selected the two horn requirements as driven cascade horn section and output section, select the principle in The shape factor to meet the requirements of the cascade horn case, by comparison of the amplification factor, the selected amplification factor of the larger horn. 2 according to the determination of the diameter of the end face of the horn and the input frequency, designed to comply with the experimental equipment of the ultrasonic shot peening cascade horn, is mainly determined by analytical method amplification factor, nodal displacements and resonator length and other parameters. Vibration theory and finite element method by means of finite element software ANSYS modal analysis of cascade horn design, extract the natural frequency of the longitudinal vibration. Design and analytical method of the resonance frequency of the cascade horn contrast, to improve a cascade horn design manufacturing feasibility. 4. Manufacturing cascade horn design, the experimental device which applied to the ultrasonic shot peening, to verify the feasibility of the practical application of the cascade horn. The ultrasonic shot peening process is simplified as the pellets hit the specimen, application software LS-DYNA finite element simulation. Drawn perpendicular to the pellets in the ejection of the test piece, with the increase in the diameter of the pellets or the speed is increased, the test piece the maximum stress and strain values ??increase, but the diameter and the speed increased to a certain extent, when the strain values ??of the maximum stress of the test piece will not be increase stabilized value. And the test pieces produced by the maximum transverse compressive residual stress is always greater than the maximum longitudinal compressive residual stress, the maximum transverse compressive residual stress in the respective directions is substantially equal. When the pellet projectile angle greater than 60 °, the maximum equivalent stress in the specimen and longitudinal compressive stress little change, but the maximum transverse compressive stress direction is no longer equivalents. Two pellets hit the same area, the maximum stress-strain values ??of the pellets and a single pill kernels impact compared with obvious increases in the same circumstances; while the pellets along different directions at the same angle impact the same area of ??the test piece than pill particles along the same direction at the same angle impact tensile residual stress generated in the test piece to be small.