| Most of the corrugated steel web girders used in the engineering are prefabricated in the factory,that is,the corrugated steel web is welded to the upper and lower flange plates in the factory.Therefore,during the welding and manufacturing process of the corrugated steel web girders,due to the impact of high temperature,plastic deformation occurs in the welding joint area.After cooling,the area where plastic deformation occurs cannot be restored to its original state,and welding residual stress will occur.The previous situation leads to a high stress field that is difficult to predict before the structure can withstand working loads,and may lead to catastrophic failure of the structure.Fatigue has always been a key concern for steel structures due to its sudden failure characteristics.The existence of welding residual stress makes it more difficult to predict fatigue performance.Therefore,the effect of welding residual stress on the fatigue life of corrugated steel web girders cannot be ignored.In this paper,a numerical simulation method for welding residual stress of corrugated steel web girders in practical engineering is proposed and verified by experiments.A fatigue performance prediction method considering residual stress is also presented,and the results are comprehensively analyzed.The following aspects of work have been specifically done:(1)This paper summarizes the development of experimental testing and finite element simulation of welding residual stress.The history of fatigue research at home and abroad and the influence of welding on fatigue performance were introduced.(2)Using the metallographic analysis software JMat Pro,combined with the specific gravity of the steel components in the specifications,the curve of the physical performance indicators of the materials used versus temperature was analyzed.The setting of the double ellipsoidal model in the welding process of the welding heat source Dflux subroutine is described in detail to make it more suitable for the welding practice of corrugated steel web beams.Based on the actual dimensions,a model of non-uniform mesh generation was established using the finite element analysis software ABAQUS.The birth and death element method is used to simulate the welding process at the weld seam.This article also provides script files for quickly establishing analysis steps and model transformations.(3)The stress calculated by the model is compared with the measured stress in the test,which proves the effectiveness of the method used this time.The temperature field changes during welding and cooling were analyzed,and the different heat dissipation conditions at various parts of the corrugated steel web beam during welding were found.Based on the stress field of welding residual stress and the distribution of residual stress at the weld,the effect of heat dissipation rate on welding residual stress is summarized.This paper analyzes the residual stress of the intermediate section,compares the stresses of the upper and lower flange plates at the intermediate section,and summarizes the effects of different plate thicknesses on the residual stress.(4)The load is loaded according to the position of the girder in the actual engineering.In this paper,Midas software is used to analyze the most unfavorable load locations and internal forces generated by the structure when a fatigue vehicle passes,and then the internal forces obtained are directly applied to the model in Abaqus.Finally,the results are imported into Fe-safe for fatigue calculation.This paper compares and analyzes the effects of considering residual stress and not considering residual stress on the stress and fatigue life of corrugated steel web girders in normal use. |
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