Theoretical And Experimental Study On Q460 Single Equal Leg Angle Axial Compression Members

In transmission towers design,it is recommended that Q460 super high strength hot rolled steel angle should be used as main members for tower structure.According to the current Code for Design of Steel Structures(GB50017-2003),an equal angle section, being a singly symmetric section,will buckle in a torsional-flexural pattern about any axis except for flexural buckling about the unsymmetric axis.In course of calculation of the ultimate load-carrying capacity,the method advanced in GB50017-2003 is too fussy and conservative,which embarrasses the generalizability and application of high strength steel.Aiming at the problem in engineering design,the test for a total of 48 Q460 single equal leg angle axial compression members has been carried out(All the members are divided into 4 groups by different kinds of sections and each group contains 4 classes of slenderness ratio).The ultimate load-carrying capacity and failure mode are investigated. The test shows,the ultimate load-carrying capacity of Q460 single equal leg angle axial compression members is much higher than ordinary steel,which is much more economical.The theoretical analysis of geometric and material nonlinearity for flexural buckling and torsional-fiexural buckling of single equal angel was made using the finite element method,in which the factors such as residual stresses,geometric imperfections were considered.Based on the experiment results and the finite element results,a simple and practical formula for stability coefficient is recommended for design purpose.The investigation shows that the calculated value is in good agreement with experimental value.