Prediction And Control On Welding Deformation Of Bogie Frame Of High-speed EMU

With the rapid development of national economy, the pressure of railway transportation increasing, the development of high-speed railway is more and more fast in our country, have a higher request for the speed of the train, safety and comfort level. The welding technology has a key role in vehicle manufacturing, welding deformation in the process of their production control is very important. As the important carrier of high-speed train and safety critical components, bogie welding framework is mainly composed of side beam, the beam steel pipe, longitudinal beam and all kinds of hoisting seat. Because of welding seam is dense and complex, frame produce larger welding residual deformation after welding.In this paper, based on SYSWELD software on the local model of the framework of typical multi-channel welding joint simulation calculation, extracting the inherent strain values, then using ABAQUS software, apply inherent strain Then using ABAQUS software analysis on welding deformation and trend of framework applying inherent strain method, and rigid fixation method is used to control the welding deformation, through changing the rigid constraint point location to confirm better holding position.The conclusion is as follow:(1) Using the inherent strain, in the case of rigid fixation method was applied to control welding deformation is feasible, under the same precision and save a lot of computing time.(2) Welding inner ribs of side beam under the condition without rigid constraint, side beam, maximum longitudinal shrinkage and warping upward of side beam respectively are2.75mm and2.1mm. Which are reduced to54.5%and57%in the rigid fixed. Side beam outside the body dose not happen bigger deformation after welding, the maximum longitudinal contraction was1.5mm, side beam becomes warped up0.7mm, so welding can meet the requirements under the no rigid fixed.(3) Beam composition welding,welding deformation of the beam pipe is tend to vertical oval from circularunder flat welding, welding deformation toward to horizontal oval under vertical welding. Because of welding deformation of flat welding is greater than vertical welding,beam pipe is still rendering vertical oval after welding. Beam biggest upward deformation of steel pipe is3.04mm, inside distance of steel tube is shortene to1.71mm,but the lateral distance increases to3.74mm, maximum longitudinal contraction is2.86mm.(4) Beam composition welding, welding deformation of flat welding is greater than vertical welding.(5) The residual deformation of total assembly framework after welding is mainly concentrated in the side beam,so rigid fixation should be put on the side beam components. Implementing symmetrical rigid constraints when the distances from the center of the side beams is0.88m, transverse shrinkage deformation longitudinal shrinkage deformation and the four corners of the height difference in the bogie frame total assembly welding respectively reduced by36%,30%and24%compared with the absence of rigid fixation conditions.(6) Under the condition of rigid fixation,effect of the welding sequence on residual welding deformation in the total assembly bogie frame welding is small.