Q460高强度钢材焊接H形截面弱轴压弯柱承载力试验研究

Experimental study on bearing capacity of welded H-section columns using Q460 high strength steel under bending and axial compression

为了研究高强度钢材中厚板焊接H形截面压弯柱的承载力,采用国产Q460高强度钢材11 mm、21 mm中厚板制作了6个焊接H形截面压弯柱,试件截面自由外伸翼缘板宽厚比分别为7、5、3,长细比分别为40、55、80。通过对Q460低合金高强度钢材的材性测试、3种焊接截面残余应力测试、各试件初始几何缺陷测量及承载力试验,进行了H形截面弱轴压弯构件整体失稳承载力的试验研究,并与采用GB 50017—2003《钢结构设计规范》进行计算的承载力对比;同时以理想弹塑性模型,综合考虑试件初始缺陷建立有限元模型,分析计算其承载力。试验及分析结果表明:Q460低合金高强度钢材具有强度高、塑性性能较好等特点;由实测截面残余应力值得到其分布形式与普通钢材焊接H形截面残余应力分布基本相同;高强度钢材焊接H形截面压弯构件承载力试验值明显高于GB 50017—2003设计公式计算值;文中采用的有限元分析方法可以较准确地计算试件的承载力。研究成果为高强度钢材在实际工程中的应用提供试验参考。

This paper presented a study on the ultimate bearing capacity of high strength steel columns under eccentric load.Through the tension coupon tests and the measurement of the residual stress of H-section,initial geometric imperfections and ultimate loads of each column,tests on six specimens of welded H-section columns with three different cross sections made by Q460 high strength steel were conducted.The measured ultimate loads were compared with the values predicted by design formulas specified in Chinese codes.FEA models were employed to simulate the results of the tests.Initial deficiencies including geometric imperfection and residual stress were considered in the FEA models.The distribution of the residual stress and the material properties used in FEA models were taken from the tests.Q460 low alloy steel has high strength and high performance plastic property.The distribution of the residual stress of welded H-section columns using Q460 high strength steel and the distribution of the residual stress using ordinary steels were basically identical.The experimental results show that the bearing capacity of welded H-section columns of high strength steel are higher than the values predicted according to the Chinese code for design of steel structures.The results predicted by FEA models fit well with those obtained from the tests.This study provides the basis for the application of Q460 high strength steel in practical engineering.