Research On Influence Of Residual Stress On Bearing Capacity Of H-section Steel Structure

Hot-rolled H-section steel is widely used as a main component in steel structures due to its excellent mechanical properties and easy construction.A large number of butt welding components are used during construction,but the residual stress of the welding will cause some parts of the components to yield in advance,affecting the bearing capacity of the steel structure.At present,there is no systematic study on the residual stress of butt welding in hot rolled H-section steels.The effects of residual stress on the bearing capacity of components and steel structures are not quite clear.This paper studies the distribution law of residual stress in butt welding of hot rolled H-section steel,and discusses the effects of the residual stress and external load superposition on the bearing capacity of the component and steel structure.The research results can provide the theoretical basis for the selection of the form and position of the welds for the butt welding of H-beams.The project under study has practical significance in engineering.This paper mainly includes the following three parts:1.The welding residual stress of the hot-rolled H-shaped steel has been simulated in the form of five kinds of butt welds to obtain the residual stress distribution law.Through the analysis and comparison,a better butt weld welding form has been provided.2.The effects of butt welding on the bearing capacity of hot-rolled H-shaped steel beams and column members have been studied.Loads have been applied on the basis of residual stress,and the effects of weld form and weld position on the ultimate bearing capacity of H-shaped steel columns and fixed beams at both ends have been examined.3.The effects of butt welding on the ultimate bearing capacity of hot-rolled H-shaped steel frame structures have been studied.Taking a two-story frame structure as an example,the effects of the form of the weld and the position of the weld on the ultimate bearing capacity of the frame structure have been examined.The results show that the distribution law of residual stress in butt welding of hot rolled H-section steel is basically consistent with that of I-beam butt welding.Butt welding residual stress has little effect on the bearing capacity of H-shaped steel column,which can be neglected.However,the bearing capacity of H-shaped steel beam is decreased,and the shape and position of the weld have different effects.The butt welding residual force reduces theelastic ultimate bearing capacity and the plastic ultimate bearing capacity of the frame structure,and the effects of different weld forms and positions are different.Taking into consideration the welding process and its effects on the ultimate bearing capacity of components and structures,the following conclusions are drawn.In the weld form 45°oblique welding is superior to flat but straight welding.When the weld is located at the beam end,the residual stress has a greater effect on the bearing capacity of the beam.When the weld is near the fixed end of the frame column,the residual stress has a greater effect on the bearing capacity of the frame structure.In the actual construction,welds should be set up to avoid these locations.