冷弯薄壁型钢拼合箱形截面立柱轴压性能试验研究

对17根冷弯薄壁型钢拼合箱形截面立柱的轴压性能进行试验研究,截面分为A、B两类,得到了各试件荷载-位移曲线和破坏特征,并将试验结果与《冷弯薄壁型钢结构技术规范》（GB 50018-2002）＂有效宽厚比法＂和美国相关规范中＂直接强度法＂、＂有效截面法＂计算结果进行对比分析。结果表明：LC和MC系列立柱的破坏模式为整体弯曲屈曲,SC系列立柱则为局部屈曲和端部承压破坏;B类试件的最大承载力大于A类截面试件的最大承载力的2倍,即有＂1＋1〉2＂的拼合效应;对于A类截面LC系列立柱,GB 50018和AISI规范公式计算结果过于保守,而对于MC和SC系列试件,公式计算结果与试验结果比较吻合;对于B类截面LC和MC系列试件,公式计算结果偏于不安全,而SC系列试件,公式计算最大承载力偏于安全。

Experimental Analysis on Behavior of Cold formed Steel Box Built up Section Columns under Axial Compression

17 specimens of cold-formed steel box built-up setion columns were tested under axial compression load.The section forms were divided into two categories： A and B.Load-displacement curves and failure characteristics of specimens were obtained.The test results are compared with the caculated results according to ＂effective ratio of width to thickness＂ in code of ＂Technical code of cold-formed thin-wall steel structures＂（GB 50018-2002）,＂effective section method＂ and ＂direct strength method＂ in AISI specification.The results show that： the failure characteristics of LC and MC series columns are overall flexural buckling,while SC series columns are local buckling and ends confined damage.The ultimate bearing capacity of B categories section columns is three times as great as that of A categories section columns,so it has the effect of ＂1＋12＂.The results calculated according to ＂GB50018＂ and AISI specification are much conservative for LC series columns of A categories section,while in agreement with test results for MC and SC series columns.For B categories section columns,the calculated results are non-conservative for LC and MC series columns,while conservative for SC series columns.