Residual Stress Analysis Of Different Welded Joints Of High Strength Structural Steel

The existence of welding residual stress is an important problem in welding.It may lead to many defects and reduce the performance of the joint.Therefore,in order to ensure the safe use of the welding structure,it is necessary to predict the welding residual stress accurately.In this paper,the analysis and Simulation of welding temperature field and residual stress at joints are carried out for plate butt joints and T joints welded by high strength structural steel,mainly including:(1)A dual ellipsoid heat source model is established to describe the welding heat source,and the welding heat source is divided into the shape of the front half part and the latter half of the ellipsoid,and the parameters of the dual ellipsoid heat source model are determined.(2)Establish flat butt joint and T joint finite element model,calculation of heat load,the butt joint,using three layer welding method,analysis of each layer of welding temperature field distribution and the different position of the welding thermal cycle;the T joint,using two layers of six welding methods,welding temperature analysis six the distribution and different points of the welding thermal cycle.(3)Analysis of flat butt joint welding layers and complete cooling after welding of transverse stress and longitudinal stress distribution in the welding position of different points,analysis in the process of welding stress varies with time,and analysis of six different paths under longitudinal and transverse residual stress along the path of the change of joint.According to the T-shaped joint,the stress distribution in different directions after the end and cooling of six welds is analyzed,and the distribution of residual stress under different paths is analyzed.(4)To reduce the welding stress and welding residual stress relieving measures,and for the butt joint,puts forward a new technique to change the three layer in the original direction of weld bead welding process on the basis of the analysis,the improved joint distribution of residual stress,and the stress distribution were compared before and changing the welding process,influence the process of change on welding residual stress.