| Steel structure has a good market prospect because of its good mechanical properties and welding properties.In the ocean engineering equipment,the application of thick plate welding is more and more extensive.Considering the connection problems of special parts,welding has become an essential means of connection.As for the thick plate welding,the selection of welding method should take the characteristics of thick plate into account,so multi-layer and multi-pass welding in thick plate T-welding has become an essential method in thick plate welding.In the welding process,the web and wing plate would be deformed due to the action of stress.In the multi-layer and multi-pass welding of T-joint,the welds on both sides would have a certain influence on the deformation of the web.Moreover,in the process of multi-layer and multi-pass welding,adjacent welds would have certain effects on each other,resulting in many difficulties in analyzing the deformation of web.Therefore,the numerical simulation of multi-layer and multi-pass welding law research in this paper has important practical value on imporving the welding quality of thick plate T-joint,and provides a certain theoretical reference for the actual production.In this paper,the finite element analysis software MSC.Marc,a platform of numerical simulation,is used to analyze the deformation of multi-layer and multi-pass welding web by thermal-elastic-plastic finite element method.First of all,the theoretical model of the welding of three T-plates with different thicknesses is established,and the welds are divided into different weld paths.Secondly,the numerical simulation of welding seam ordering was carried out for T-plate multi-layer and multi-pass welding of different thicknesses respectively,and the results of minimum deformation under different ordering were obtained respectively.Then,the welding speed is analyzed,and the welding speed is changed when the best results are obtained.Numerical simulation is carried out respectively to obtain the best welding speed.Finally,under the condition of synthesis of the above two kinds of results,the welding direction is adjusted to a certain extent,and after a certain arrangement and combination,the numerical simulation result of the minimum deformation of the web is finally obtained.The numerical simulation results show that the web deformation of multi-layer and multi-pass welding is studied by MSC.Marc software,and certain rules are obtained.In the welding process of double-unilateral V-groove,the closer the weld is to the blunt edge,the greater the influence on the deformation of the web,and the closer the weld is to the outer end of the plate,the smaller the influence on the deformation of the web.The welding sequence of the weld has the greatest influence on the deformation of the web,among which the welding sequence of the first six welds plays a key role,resulting in the largest deformation.When the welding sequence is1→2→4→3→6→5→9→10→7→8 at 30 mm,the minimum welding deformation is0.4274 mm.When the welding sequence is 1→2→4→3→6→5→7→9→10→13→8→11→14→12 at 40 mm,the minimum welding deformation is 0.3730 mm;When the welding sequence is 1→2→4→3→6→5→9→10→13→7→8→11→12→15→16→17→14→18→19→20 at 50 mm,the minimum welding deformation is 0.1050 mm.The welding speed also has a certain influence on welding.When the welding speed is10mm/s,the welding direction of 30 mm thick plate changes when the welding direction of No.3 and No.7,the deformation of 40 mm thick plate changes when the welding direction of No.3 and 50 mm thick plate changes when the welding direction of No.5,11 and No.12 is respectively,0.2294 mm,0.1279 mm,0.1023 mm,the welding deformation has a certain change,but not as much as the welding sequence of welding,with a certain limit. |
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