Local-overall Interaction Buckling Analysis Of High-strength Steel Equal Angle Struts Under Axial Compression

Compared with ordinary steel, high-strength steel has a significant advantage in such aspects as the bearing capacity, economic efficiency, sustainable development,environmental protection, etc., with good prospects for development[1], and the applications of high-strength steel equal angle struts under axial compression in the transmission tower and building structures are gradually increased[2-3]. Due to the increased strength, the width-thickness ratio limits of high-strength steel components are reduced, even with the same width-thickness ratio, the panel is also more prone to local buckling than ordinary strength steel member. At the same time, the local buckling of the plate is also produced in advance as a result of the initial imperfections, and because the plate has a certain post-buckling strength, the local buckling of plate under normal circumstances does not mean that the overall carrying capacity of the member is lost, but to reduce the overall stiffness and stability bearing capacity of the axial compression. Therefore, as the load increases, the overall buckling is more likely to occur in advance. In these case,the width-thickness ratio of high-strength steel angle exceed the limit more easily than that of ordinary steel, the local buckling is easy to happen earlier than the overall buckling, and the post-buckling strength should also be developed, local-overall interaction buckling analysis of high-strength steel equal angle struts under axial compression is particularly important. In view of this, the following research has been done in this paper:(1)Four calculating ways of the bearing capacity of axially compressed members are compared with their scope application and characteristics. By this way, it’s found that the interactive buckling method is more suitable for calculating the local-overall interaction buckling bearing capacity of axially compressed members.(2)Using the finite element software ANSYS, numerical analysis of the high-strength steel equal angle struts under axial compression is made, and then the validity of the finite element model establishment and analytical method is verified.Subsequently, the local-overall interaction buckling modes are obtained and analysed.(3)With different width-thickness ratios of the angle leg, yield strength and slenderness ratios, the impact is analyzed on the local-overall interaction buckling ultimate bearing capacity in such aspects as interaction buckling ultimate bearingcapacity, nondemensional ultimate bearing capacity and load-displacement, then the results are presented.(4)By combining the interactive buckling method, the interactive buckling formulas are obtained which applied to the high-strength steel equal angle struts under axial compression. The rationality of the recommended formulas is proved by comparing with finite element analysis together with effective yield strength method so that they can provide a reference for design and application of high-strength steel equal angle struts under axial compression.