460MPa高强钢箱形截面轴压柱局部稳定有限元分析和设计方法研究

为研究460MPa高强度钢材等边箱形截面轴心受压柱的局部稳定受力性能和设计方法, 该文采用有限元软件ANSYS建立有限元模型, 考虑残余应力和局部初始几何缺陷的影响, 对3组共10个460MPa等边箱形截面轴心受压短柱的局部屈曲进行了有限元分析, 并将极限承载力计算值与试验实测值进行对比, 结果证明该模型能够准确分析计算460MPa高强度钢材等边箱形截面轴心受压柱的局部屈曲受力性能。利用该模型进行有限元参数分析, 与钢板的宽厚比相比, 钢板厚度、钢板长宽比、残余压应力值和局部初始几何缺陷幅值等因素对局部屈曲受力性能的影响都很小。将试验实测值和参数分析的结果与中国、美国和欧洲钢结构设计规范中箱形截面局部稳定设计曲线进行对比, 表明现行规范的设计方法不够安全。该文提出的建议设计公式适用于460MPa高强度钢材等边箱形截面轴心受压柱局部屈曲极限应力的设计计算。

FINITE ELEMENT ANALYSIS AND DESIGN METHOD STUDY ON THE LOCAL BUCKLING OF 460MPa HSS BOX SECTION AXIAL COMPRESSED COLUMNS

In order to analyze the local buckling behavior and the design method of 460MPa high-strength-steel square-box-section columns under axial compression, a finite element model is developed by using the finite element software ANSYS, with the accurate simulation of residual stress and the local initial geometric imperfection, so as to analyze the ultimate loading capacity of 10 welded box-section stub-columns under axial compression considering local buckling. Compared with the test results, the finite element model is proved to be accurate enough for further analysis. With the finite element model, a parametric analysis is conducted, the results of which indicate that the width-thickness ratio is the most important influence factor. The test results and the finite element analysis results are compared with the design methods in Chinese, American and European codes, suggesting these design methods are not safe enough. New design formulae are proposed for the design of the local buckling of 460MPa high-strength-steel box-section columns under axial compression.