中外钢结构规范钢梁局部稳定性计算对比研究

Comparative Study on the Calculation Methods of Local Stability of Steel Beams as per Chinese Standards,EU and American Standards

钢梁是钢结构工程中最为常见的受力构件之一,其局部稳定性是设计关注的重点。文章介绍了中国、美国及欧洲钢结构设计规范中对钢梁局部稳定性计算方法的规定,分别以三种规范推荐的方法对受弯钢梁局部稳定抗剪承载力进行了计算分析,结果表明:(1)中国钢结构设计规范规定了翼缘自由外伸与其厚度的相对值,确保设计上翼缘不发生局部屈曲;(2)美国钢结构设计规范规定,根据板件是否发生局部屈曲将钢梁进行分类,若翼缘的宽厚比超过限值,则钢梁截面为细长型,应进行翼缘的局部屈曲计算;(3)欧洲钢结构设计规范规定,根据转动能力的强弱把截面分为四个类型,其中IV类截面最为薄宽,一般在钢梁达到屈服前就会产生局部屈曲;(4)受弯钢梁局部稳定抗剪承载力计算结果表明,中国规范和欧洲规范的计算结果相近,美国规范的计算结果略大。

Steel beams are the most common force members in steel structure engineering, while the local stability of steel beams is the focus of design. In this paper, the regulations for the local stability of steel beams stipulated in steel design specifications of China, the United States and European are discussed respectively. Shear capacity of local stability of curved members is calculated and analyzed with 3 methods recommended from 3 specifications, the results show： （1） China＇s steel structure design code stipulates the relative value of the free extension of the flange and the thickness of the flange to ensure that the flange has no local buckling. （2） According to the design rules of American steel structure, the steel beams are classified according to whether the local buckling of the plates occurs or not, the width-thickness ratio of the flange exceeds the specified value, the section of the steel beam is slender, and the local buckling calculation of the flange should be taken into account. （3） The European Code for Design of Steel Structures stipulates that cross-sections are divided into four types according to their ability to rotate, of which Class IV is the thinnest, and local buckling usually occurs before the steel beam reaches yielding. （4） The calculated results of local stable shear bearing capacity of steel beam flexural members show that the calculation results of Chinese and European codes are similar, and the calculation results of American codes are slightly larger.