Study On Welding Experiment And Simulation Of I-section Steel Curved Beams

With its unique structural form,curved beams are widely used in bridges,buildings and industrial plants with special needs.There is a lack of research on the influence of welding process on curved beams,and the current focus is on straight beams.In this paper,the stress and deformation of welded steel curved beams with I-section will be measured and analyzed based on 3D scanning technology,and the welding process of steel curved beams will be simulated and studied with the finite element analysis software ABAQUS.The main research contents and results are as follows:(1)Based on the idea of reverse engineering,the 3D scanning technology was used to scan and model the steel curved beams before and after welding,and the 3D model was imported into the finite element software to measure the welding residual deformation.Through the load capacity analysis and test comparison of each member model,the feasibility of the numerical simulation method based on 3D scanning technology to establish the finite element of curved beam members was verified.Subsequently,the welding residual stress was measured using the cut strip method to study the distribution of residual stress in the curved beam,which was used as the basis for subsequent verification of the welding finite element model.(2)The sequential coupling method was adopted,and the finite element software ABAQUS was used to call the DFLUX subroutine to simulate the temperature field in the welding process of the I-section steel curved beams.Then the temperature field was used as the initial temperature load to calculate the stress field and deformation field.The residual stresses and deformations obtained from the simulation were compared with the experimental measurements,the accuracy of the finite element welding model is verified.(3)The validated model was used to simulate the curved beams with different welding sequence,welding speed and different curvature radius,and analyze the effects of different processes on the welding temperature field,stress field and deformation.The results show that cross-welding from the span to both ends gives a smaller value of longitudinal residual stress and deformation;Welding speed has a great impact on the welding process,and the faster the welding he welding speed has a great influence on the welding process.Through comparison,it is found that the faster the welding speed,the smaller the welding temperature value,the smaller the corresponding longitudinal residual stress and deformation;For beams with different curvature radius,the analysis found that the peak temperature field and heat-affected zone distribution range increase with the curvature radius become larger,and the equivalent stress and longitudinal residual stress peak difference is not significant.In addition,the distribution of residual deformation in curved beams is completely different from that in straight beams.Curved beams produce larger displacements along the X-direction at the center of the web,and there is a tendency for the flanges to flip outward near the span center.(4)On the basis of the existing curved beam theory,the calculation formula of ultimate bearing capacity of welded I-section steel curved beams is analyzed.Through the fitting of multiple groups of test data,and considering the welding residual stress and deformation and various shape parameters of the curved beam,a simplified formula for the ultimate bearing capacity of the welded I-beam is obtained.The ratio between the test results and the formula calculation results is within the acceptable range.