Research On Cold Bending Process And In-plane Bearing Capacity Of Arched Component

With the development of economy,large-span space structure is the fast-growing system structure at present with abundant structural forms,which leads to the increasing demand of curved component in many industries,such as the pipeline transportation of oil and gas in energy industry,space grid structure in large gymnasiums and offshore platform,etc..Components experience hot bending or cold bending to generate the required shape,especially the residual stress and material changes produced by cold bending arouse many concerns.However,no matter in which way to bend,the component will be accompanied by the generation of the resilience and residual stress after bending.Therefore,it will generate some errors in the distributionof residual stress andthefinal amount of springback between the actual value and the true value in the curved component,which not only affect the accuracyin site installation but do harm to the bearing capacity of the whole structure caused by residual stress of the component.In recent years,some scholars havestudied about the cold-formed technology and forming process achieving some important data and conclusion.However,there's few scholars or relevant specification using continuous multistage bending processorthe way of bending in the middle to do researches on the bending process of the component.This paper selects the steel tube with circular section as the research object and uses the way of bending in the middle to discuss the different effects of process parameters on the quality of the component of arched tube after bending by numerical simulation analysis.This paper mainly focus on the following aspects:(1)To establish the finite element analysis model of the cold bending processand to determine the constitutive relation of cold bending pipe.(2)To study on the distribution of residual stress,residual strain,wall thickness,ovality,and sagittal heightbased onthe finite element analysis of the section and multi section bending of steel pipe.(3)The influence of three process parameters of cold bending(including cylinder displacement loading,radius of curvature of loading plate and support spacing)on the indicators of the steel pipe after forming will be explored.(4)The load typeof arched components will be discussed.(5)The in-plane stability of arched componentswill also be discussed after taking the initial defects into consideration.Through the further study on forming process,it has an important guiding significance for the factory to produce the archedcomponents withhigh quality and formulate relevant regulations.