Research On Residual Stress Characteristics Of Cold-formed Profiles Based On Numerical Simulation

Because of its excellent technology and economy,the cold-bended profile components are widely used in the shipbuilding industry.In this paper,the cold bending process of profile is studied.Profile component is the basic structure of hull structure.The processing of profile usually uses CNC Ship Cold Frame Bender,which applies external force to the profile by means of machinery,so that the profile produces plastic deformation.In this paper,ship angle steel,T-section steel and ball flat steel are taken as the research objects,and the cold bending law of section steel is studied by the method of numerical simulation and confirmatory test.In this paper,ANSYS/LS-DYNA software is used to model the cold bending forming process of the profile,including geometric model,finite element model and progressive approximation forming model.Influence and its residual stress characteristics,and finally use the stepwise approximation results to explore the forming law of cold bending.The above research work has reached the following conclusions:（1）In the curve of bending curvature and rebound curvature,the rebound curvature of Web flange increase first and then decreases slightly with the increase of bending curvature.（2）The material of profile has influence on the residual stress.The higher the strength of the material is,the greater the residual stress of the profile is,but the material has little influence on the distribution of the residual stress.（3）In the process of approaching bending,the residual stress of profile decreases gradually,and the stress concentration of Web flange is improved.Therefore,approaching the bending process step by step is helpful to improve the fatigue strength of components.（4）The numerical results show that there is a linear relationship between the bending amount and the springback amount.This characteristic is similar to the experimental results.In this paper,the verification test of cold bending of profile is carried out,and the numerical simulation results are compared with the test results.The results show that the numerical values of the two are relatively close,and the change rule is consistent.In conclusion,some significant results have been obtained in the material residual stress characteristics and related work in the cold bending process of profiles,which has certain reference significance for improving the bending process.