Design And Research Of Ultrasonic Impacting Equipment For Relieving Welding Residual Stress

At present, welding structure is widely used in relative field of national economy, we can say that the use of welding structure have promoted the develop of modern industry to some extent, But owning to the existing of welding residual stress and distortion, it can straight affect the capability of welding structure, safe reliability and manufactory feasibility. So it is one of the important issues of welding all the time.Ultrasonic impacting treatment is a new procedure of improving the welding residual stress. This paper describes the development in of ultrasonic impacting equipment used for ultrasonic impacting treatment.The technology of ultrasonic impacting uses the high power ultrasonic to push the impacting tool at the frequency of 20KHz and impact the metal surface, because of the high frequency, efficient and high energy of ultrasonic, it can generate major plastic deformation on metal surface, at the same time, the ultrasonic impacting changes the original stress field, generates a certain amount of compressive stress, and strengthen the Position of ultrasonic impacting. This paper firstly analyses the structure and functions. of ultrasonic impacting equipment for relieving welding residual stress, and then built an overall plan of ultrasonic impacting equipment. Ultrasonic impacting equipment is made of actuator and ultrasonic generator. Actuator is made of transducer, amplitude transformer and impact block. Ultrasonic generator should have main circuit which can generate enough power and alternating current of required frequency, frequency tracking system and power output control system.Because of the giant magnetostrictive materials'magnetostriction coefficient is the biggest of all the materials at the room temperature, and exceed an order of magnitude of piezoelectric constant, it can generate giant strain in lower field, it has the advantage of high electromechanical coupling factor, high energy density and fast response time. So this paper has designed a actuator which's core components is giant magnetostrictive transducer, and has calculated aim at giant magnetostrictive transducer and designed it's concrete structure and size, used the software of CAXA to draw a part of parts'two dimensional diagram and giant magnetostrictive transducer's overall structure sketch map, then used the software of CATIA V5 to proceed the transducer's three dimensional visual solid modeler. Then this paper has designed conical amplitude transformer and impact needle, and used the software of CATIA V5 to proceed the conical amplitude transformer and impact needle's three dimensional visual solid modeler.This paper analyses the process of ultrasonic impacting, finds out the frequency and power's variable situation in actual practice, and analyses electroacoustic characteristics and handling characteristics of ultrasonic impacting equipment, comes up with structure and functions'idea of the overall designing, establishes the main circuit of ultrasonic generator, and accomplishes the design of circuit of frequency tracking system and power output control system, Then uses the software of MATLAB to simulate the phase discriminator of frequency tracking system.At the end of this paper, summarizes the paper and previews the work in the future.