| The paper study uses the forming process of Q345B cold-formed square tube manufactured by cold-formed rectangular tube as the object.Firstly,based on the analysis of the basic theory of cold roll forming,the finite element model of the cold-curved rectangular tube before welding is established by finite element software ANSYS,it is concluded that the residual stress of cold bending square rectangle tube distribution rule,and the correctness of the simulation results is verified.On this basis,the influence of different process parameters on the cold-bend built-in stress is analyzed.Then the finite element model of the welding process is established,and the temperature field of the cold-formed rectangular tube is simulated and verified,and welding built-in stress distribution of the cold joint pipe is obtained.From the analysis of result,residual stress with the increase in the thickness of the tube increase before the cold bending square tube is welded,the yield strength of the material has a great influence on the residual stress of the square tube,the residual stress increases with the increase of yield strength,and little impact roller spacing on cold-formed residual stress.And square corner frequency of the maximum residual stress than the upper corner of the square,and the maximum residual stress appears in the plane of the welding center rather than in the corners in the square cold forming section.Besides,residual stress of tube outer surface is mainly tensile stress,the inner surface is mainly compressive stress or close to zero.The researches show that the welding equivalent residual stress is the largest in the weld center in the high-frequency induction welding section,and the longitudinal residual stress of square value is much larger than the transverse residual stress value.Besides,the heat affected zone also has a large residual stress,and the effect of welding heat on the stress outside the circumferential 15 mm can be ignored. |
PDF Full Text Request