Research On Numerical Simulation Of Ultrasonic-assisted MIG Welding Arc

This paper is about the numerical simulation of the welding arc of ultrasonic assisted MIG welding.Using the fluid mechanics software,combined with the theory of fluid dynamics and Navier-Stokers equation and compiled the User Define Function(UDF)program for secondary development,the numerical simulation of the welding arc of conventional Melt Inert-gas(MIG)welding and ultrasonic assisted MIG(U-MIG)welding is conducted.A corresponding mathematical model was established based on the welding platform,to explore the conventional MIG welding with U-MIG welding arc differences in the various physical fields,and analyze the ultrasonic vibration on welding arc shape and physical field of the influence and effect,for the development of the ultrasonic compound welding to provide important theoretical basis and experimental value,also for numerical simulation of welding process provide valuable reference.The simulation software used in this study is ANSYS 18.0.The Fluent module is used to establish the mathematical model of welding arc of ultrasonic assisted MIG welding.According to the actual requirements,the mesh of appropriate size is divided,and the compiled secondary development program is imported into the governing equation using the external interface UDF.On this basis,the ultrasonic wave with fixed parameters is applied,and the welding arc under different current conditions is simulated by software,and the relevant physical field data is collected.The simulation results show that radial ultrasonic wave can compress the welding arc.The temperature nephogram shows that the ultrasonic wave can increase the temperature and distribution of the arc,but the effect gradually decreases with the increase of current.It also changes the distribution of current density and pressure field.The potential simulation results show that the voltage value of U-MIG welding decreases under the same current condition,indicating that ultrasonic has a positive effect on MIG welding.In order to verify the accuracy of the numerical simulation,a welding experiment with the same welding parameters was carried out in this study.The dynamic arc pictures in the welding process are collected by high-speed camera,and the pictures are processed and analyzed by post-processing software.The results show that the welding arc is compressed obviously after the addition of radial ultrasonic wave,the droplet transition period is shortened,and the droplet neck-shrinkage radius is reduced.The comparison between the simulation results and the experimental results shows that the welding arc model and simulation results have good reliability and accuracy,which has a certain reference value.