Study On Numerical Simulation Of Rotating Arc Welding Heat Model For Corner Joint

The rotating arc sensor welding is a technique essential to the welding industry and is the focus of the study abroad welding industry at corner joints, because used good mechanical properties of the workpiece and the weld bead width.etc, after the weld cooling.With the development of construction, shipbuilding and other industries, the quality of the welding workpieces increasingly demanding. The urgent need characteristics of rotating arc welding for corner joints were studied.During the rotating arc welding process,it is own characteristics,the welding process factors and cross-cutting role of factors duing the rotating arc welding process of the weld joints angle,so it increased difficulty and other issues for research weld, the weld pool formation and deformation of the workpiece after welding, weld quality defects.Further more it is rotation of the wire ends of the rotating arc corner joints so that welded heat source model is more complex to compared with ordinary welding.The difference between the different factors and welding heat welding parameters would lead to welding temperature field, stress field and after welding deformation of the workpiece differently.In order to obtain better quality control o f welding deformation,it is necessary to optimize the welding parameters and study its numerical simulation.Based on the literature analysis and preliminary studies in this paper,let the clockwise of rotating arc, rotation radius is 3mm and the welding torch angle is45?,with the thickness of 5 mm carbon steel as base material,using MAG(Metal Active Gas Arc Welding) welding.First of all welding parameters were optimized, combined with the empirical method and references,and consider the various factors interact,in minitab software hypothesis welding voltage,welding current respectively with welding speed and the role of the rotation frequency cross each other effect, and also the rotation frequency with welding speed, wire extension is cross-cutting impact. Using welding voltage, welding current, welding speed, rotation frequency, stem elongation and gas flow as method of 6 factor and 3 levels, and using Taguchi method to establish the orthogonal model. According to the regression analysis, variance analysis method and the mean value method, derived relations and good welding parameters between the different factors and the results showed that here will be distortion phenomenon at the fraction of weld quality in 11.8 points, weld width error in the vicinity of 1.4, weld reinforcement error 0.31 to 0.34.According to establishment heat source of rotating arc for corner joints welding,consider its characteristics and weld the introduction of the torch angle, builded new welding heat source model on the basis of improvements of double ellipsoid heat source,so that it can more accurately describe the formation of rotating arc welding process.In the paper,hypothesis, the angle of the torch is 45?, it analyzes the fillet weld,made asymmetry characteristics of asymmetrical parameter distribution,obtained the relationship between the parameters of weld heat,obtained the scale factor of the width k= 1.11,established equations of rotating arc fillet welding ends trajectory and analyzed the movement of the wire ends according to different rotational frequencies.For welding workpiece,the size of the bath shape,weld characteristics,the workpiece residual stress distribution,crack size distribution and deformation are closely related to the quality of the workpiece.In order to solve the problems duiing welding,so it need numerical simulation of temperature distribution and the distribution of stress field of rotating arc welding for corner joints.Fistly,obtained physical materials under different temperature and enthalpy value according to the literature.Secondly,in the Ansys software,used SOLID70 unit to makes simulation analysis of temperature field,and used SOLID5 unit directing coupling to stress field numerical simulation.Using drag and swept meshing in the weld and heat affected zone, using the mapping grid else where,and using cell assemblies and components to kill or activate the node.Set the initial conditions and boundary conditions based on the actual welding conditions, improved rotating arc drawn quality scores by using physical and chemical processing and inversion algorithms to numerical simulation.It is results that the bath formation process of rotate arc welding for corner joints;analyzed the thermal cycle curve at different times,the dynamic heat temperature field changes results that close to the high energy side,easy to form undercuts, and near the center of the front of the heat source temperature is higher than at the center, and later,on the side heat gradient greater than the lower plate;Study on the dynamic stress distribution,stress distribution after cooling and different paths stress change problems results that the initial welded angle of the epipleural deformation is °3 10′than the lower plate is °2 30′;deformation angle of the lower plate is °3 20′at the end of the welding, the upper plate deformation angle is °2 28′ smaller than no rotation of deformation;close to the heat affected zone is about 1.31 mm, the tensile stress a sharp increase in the stress variables decreases,the incremental slope is negative;after cooling down,the epipleural in X,Y,Z and the maximum value of the degree of distortion of the residual stress is less than the lower plates,and the lower plate more irregular deformation occurs hazardous area higher frequencies.Results of this study that is providing a theoretical reference for rotating arc welding process parameters at corner joints,tructural design,welding fixture design,and construction to prevent deformation of the workpiece to promoted rotating arc sensor welding application and promotion.