Study On The Local Buckling Behavior Of Hot-rolled ? Section Based On OIC

Yield and buckling are the two most common failure modes in steel structures.For components,the overall buckling and material yield are most likely to occur,while the local buckling and material yield is suitable for plates.The foreign standard adopts the?section classification method?for design,and different types of sections adopt different design formulas.Specifically,plastic design is used for Class?and Class?cross-sections,elastic design is used for Class?cross-sections,and Effective Width Method?EWM?is used for Class?cross-sections,which creates faults between Class?and Class?cross-sections,and With the popularity of high-strength steel,the cross-section becomes softer and thinner,and EWM is more tedious to implement.The"Direct Strength Method?DSM?"and"Continuous Strength Method?CSM?"proposed in recent years have overcome the deficiencies of"cross-sectional classification method",but the scope of application has been limited.So Professor Boissonnade proposed the"Overall Interaction Concept"method.This method is based on the adapted Aryton-Perry formula.It is applicable to all types of sections from thick to thin.Jonna made the study of the local buckling ultimate bearing capacity of a square rectangular section use this method.However,the domestic and international studies on the local buckling performance of the I-section in hot rolling are still poor.In this paper,the finite element software ABAQUS is used to simulate the local buckling behavior of hot rolled I section under axial compression and pure bending.The influence of initial defects and residual stress on the local buckling ultimate bearing capacity of the cross section is considered.The correctness of the model is established,and then the variable parameters that affect the local buckling ultimate bearing capacity of the section are analyzed.Based on the finite element calculation results,the calculation formulas of the OIC-based hot rolling I-section axial compression and pure bending local buckling ultimate bearing capacity are proposed.Comparing the calculation results of the proposed formula with the results of normative calculations in various countries and conducting a reliability analysis of the proposed formula using the method in EN 1990 Annex D[63],some useful results are obtained as follows:In this paper,the OIC method is preferred as the basis for formulating axial compression and pure bending ultimate bearing capacity for hot rolling I-sections.The local buckling regularization ultimate bearing capacity of the cross-section varies with different thickness variation modes,and there are HWV?29?HFV?29?HWFV.In this paper,the HWFV model is used.The study shows that the steel yield grade has no significant effect on the axial compression and pure bending regularization ultimate bearing capacity for hot rolling I-sections,the maximum difference is 3%.Therefore,it is not taken into consideration when formulating the OIC formula.The aspect ratio H/B has a significant influence on axial compression and pure bending regularization ultimate bearing capacity for hot rolling I-sections,the maximum difference is up to 34.7%,so it should be considered when formulating the formula.This paper proposes The OIC formula for hot rolling I section under axial compression and pure bending,meanwhile,determining the quantitative relationship between the aspect ratio H/B and the four main parameters?,?_CS,?₀,?;No matrer for axial compression and pure bending,GB,EC3,DSM calculation results are more or less than the finite element calculation results in a specific area,that is,they are either unsafe or conservative,and the formula calculation results are closest to the finite element results,with the smal est variance and the highest excel ent performance.