Buckling behavior and design of large-section angle steel columns under axial compression

Abstract

Large-section angle steel (LAS) columns are gradually used in building structures due to their high bearing capacity. However, the research on the instability mechanism and design method of LAS columns with yield strength below 420 MPa still needs to be improved. In order to study the axial compression stability of LAS columns, the buckling mode of LAS columns is analyzed by theoretical analysis, and a total of 192 specimens (including Q345 and Q420) are subjected to axial compression tests. An accurate finite element model was established based on the test data, the main influencing factor of the buckling behavior of LAS columns was explored, and the buckling process and characteristics of LAS columns were revealed. The results show that the buckling mode of the LAS columns is flexural buckling, and local buckling does not occur. The secondary warping stress does not affect the buckling mode and buckling factor of LAS columns. The constitutive model of the current design method underestimates the buckling capacity of short LAS columns. Based on the parametric studies, a new column curve is proposed to predicate the buckling factor of the LAS columns.