Numerical Analysis Of Welding Residual Stress And Deformation Of Large Transformer Box Structure

The transformer box is an important part of the entire transformer,which plays a bearing role on the transformer oil and internal components.Welding plays an important role in the transformer box manufacturing process,and welding will inevitably produce welding residual stress and deformation.Welding residual stress and deformation not only affect the stability,static load strength and assembly accuracy of the entire transformer box structure,but may also cause cracks under the action of external loads,resulting in transformer oil leakage.At present,we know very little about the welding residual stress and deformation distribution of the transformer box structure.Therefore,research on the welding residual stress and deformation of the transformer box structure can not only obtain the distribution law of welding residual stress and deformation,but also Guide the welding of transformer box to lay a good foundation for ensuring welding quality.In recent years,with the rapid development of computer technology and the continuous improvement of welding theory,numerical simulation technology has been widely used in the prediction of welding residual stress and deformation.In this paper,with the help of ANSYS platform,the thermo-elastoplastic finite element method is used to numerically calculate the residual stress and deformation of the transformer box structure.The typical welding seam in the welding of transformer box structure-butt welding seam is numerically calculated.By studying the influence of groove form on the welding residual stress and deformation of butt weld.The results show that,regardless of welding residual stress or deformation,the X-shaped groove is significantly lower than the V-shaped groove and K-shaped groove,and the V-shaped groove is higher than the K-shaped groove.The other typical welding seam of the transformer box structure,fillet weld,is numerically calculated,and the influence of the distance of the web into the wing plate on the welding residual stress is studied.The results show that as the incorporation amount increases,both the transverse stress and the longitudinal stress decreaseBased on the analysis of typical welding seam optimization,numerical analysis is carried out on the welding residual stress and deformation of the large transformer box structure.The results show that there are multiple peaks in both longitudinal stress and transverse stress along the welding direction;the longitudinal stress is much higher than the transverse stress and exceeds the yield strength of the material;there is a peak stress at the weld junction.The deformation after welding is mainly concentrated on the box wall and the box cover,and there is a peak displacement at the junction of the box cover and the box wall weld.