Multi-sided steel tubular sections are commonly used in many structures such as high mast lighting and sign supports. Current AASHTO standard for Structural Supports for Highway Signs, Luminaires, and Traffic Signals provides width-thickness limits to check for local buckling of octagonal (8-sides), dodecagonal (12-sides), and hexadecagonal (16-sides) steel tube sections when they are subjected to axial compression and bending. Although multi-sided tubes are used in many structures, very limited study has been conducted to evaluate the slenderness limits of these thin-walled sections. This paper presents a finite element (FE) analysis based study of local buckling of multi-sided steel tubular sections. A nonlinear FE model is developed for this study and validated against experimental results from stub column tests of 8-, 12-, and 16-sided cross-sections. The FE model is then used to analyze a series of multi-sided tubular sections subjected to axial compression or pure bending. Results from FE analyses are used to evaluate the slenderness limits specified in different standards (AASHTO, ASCE, and Eurocode 3). FE analyses show that AASHTO provided compact limit for many multi-sided tube sections are non-conservative when subjected to flexure and might need to be revised. Also, current non-compact section limits are quite relaxed for the sections subjected to pure bending. Based on FE results, revised compact and non-compact limits have been proposed for octagonal, dodecagonal, and hexadecagonal multi-sided tubular sections. Moreover, FE analyses indicate that the non-compact limit of the hexadecagonal section can also be used for the other two sections under axial compression.

多边钢管型材通常用于许多结构，例如高桅杆照明和标志支撑。公路标志、灯具和交通信号的结构支撑的现行 AASHTO 标准提供了宽度-厚度限制，以检查八边形（8 边）、十二边形（12 边）和十六边形（16 边）钢管截面的局部屈曲当它们受到轴向压缩和弯曲时。尽管多边管用于许多结构，但对这些薄壁部分的细长极限进行评估的研究非常有限。本文提出了基于有限元 (FE) 分析的多边钢管截面局部屈曲研究。为这项研究开发了一个非线性有限元模型，并根据 8-、12-、和 16 边截面。然后使用有限元模型来分析一系列承受轴向压缩或纯弯曲的多边管段。有限元分析的结果用于评估不同标准（AASHTO、ASCE 和欧洲规范 3）中规定的细长限制。有限元分析表明，AASHTO 为许多多边管段提供的紧凑限制在受到弯曲时是非保守的，可能需要修改。此外，对于承受纯弯曲的截面，当前的非紧凑截面限制相当宽松。根据有限元结果，针对八边形、十二边形和十六边形多边管截面提出了修正的紧凑和非紧凑限制。而且，