Exprimental And Theoretical Study On Q460 Single Equal Leg Angle Eccentrical Compression Members In Sub-structure

Along with our country electric power industry keep high speed development, 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. Now most of the specification in our country has not added the Q460 high-strength angle members to the list of available materials. To verify that if the formula of our " Code for design of steel structures " GB50017-2003 and the United States" Design of latticed steel transmission structures " ASCE-1997 to calculate stability and bearing capacity is applicable for eccentrically compressed Q460 hot-rolled members,carried out experimental study and theoretical analysis by single strut, and the suggestion for the specification has been presented.To verify that if the actual project boundary conditions simulated by the single strut experiment is able to respond the mechanical properties and constraints of the real structure, if the correction formula proposed by single strut experiment is reasonable and to further study the overall mechanical behavior of Q460 high strength angle in the structure the experiment study and and ANSYS finite element analysis in sub-structure were carried out.Comparison of the above analysis shows that:the small slenderness ratio compression members are main controlled by local buckling and the large slenderness ratio compression members are controlled by overall buckling.The compression members bend round connection leg, with twisting deformation taking place at same time. Experimental phenomena and mechanical properties are almost the same with the single strut's.There are small differences in caculating overall stability value by sub-structure correction formula and the single strut correction formula.The result of the amendment to the specification GB50017-2003 shows that:the value caculated by sub-structure correction formula is larger than the value caculated by the single strut correction formula and the rate is 1.2%～7.9% less than 10%. The result of the amendment to the specificationASCE10-1997 shows that:the value caculated by sub-structure correction formula increase the value caculated by the single strut correction formula -2.0%～+0.7%.Therefore, actual project boundary conditions simulated by the single strut experiment is reliable and the correction formula is reliable for providing reference for engineering design.