Research On Dynamic Stability Of Stir-welding Head Of An Axial Vibration Combined Spin Consumable Node Friction Welding

The axial vibration combined spin consumable node friction welding is a kind of friction welding on the basis of the common friction stir welding,in the mixing head axial attached a high-frequency periodic vibration,and combined with consumption type welding method of new welding technology.The innovative welding technology using vibration with high frequency and small displacement of the welded work piece for bidirectional mixing and to improve the mixing head on weld of upsetting extrusion,and the use of high frequency longitudinal vibration of high frequency pulse impact force to improve the mixing head upsetting force,also in welding the weld area of welding material and well improve the reliability of welding.The consumption of axial vibration very stirring head through the shaft shoulder and the welding between the surface friction,rotation and generated by the welding of friction and the high frequency longitudinal small displacement vibration friction welding energy needs.At the same time,another important function of the consumption of the pole is to provide the mechanical stirring force for the plastic material in the weld zone,so that the flow of the material is more reasonable,so as to form a dense microstructure.Consumption very stirring head as axial vibration of rotating consumption extremely friction welding technology innovation the key execution unit,the consumption of the mixing head in the welding process stability will directly determine the welding trajectory accuracy,welding friction vibration energy control,welding quality,reliability and welding strength and ultimately affect the precision and the reliability of the welding.Due to the welding technology in the mixing head is periodic high-frequency and small vibration displacement,so the mixing head stability problem belongs to the stability of truss structure dynamic stability problem.The 3D motion trajectory and mechanical characteristics of stir-welding head is studied in thi paper;Based on truss structural dynamic differential equations and consumption relationship between very stirring head of the dynamic stability critical load and critical length and critical frequency and parameters,and study the relationship curve;at the same time the stirring head the dynamic critical unstable region are studied;finally the application of ANSYS finite element simulation software to consume very stirring head theory results are verified.