高强度钢材箱形截面轴心受压短柱局部稳定试验研究

针对高强度钢材焊接箱形截面柱的局部稳定受力性能,对4个Q460钢材等边箱形短柱进行轴心受压试验。根据试验结果分析试件的局部屈曲应力、极限应力随板件宽厚比的变化规律,并将试件的局部屈曲应力、极限应力与我国、美国、欧洲钢结构设计规范以及陈绍蕃建议的相应设计方法和计算公式进行对比分析。结果表明,钢板的宽厚比越大,试件截面的利用率越低,局部屈曲后强度越富余;我国钢结构设计规范中对于试件的局部屈曲应力的计算公式不适用于等边箱形短柱;对于等边箱形短柱的极限应力,美国、欧洲钢结构设计规范和陈绍蕃建议的设计方法的计算结果较为接近,且均略高于试验结果,这3种设计方法都是可行的。进一步修改已有的计算公式,以适用于计算Q460高强度钢材等边箱形短柱的局部屈曲应力;建议采用陈绍蕃建议的设计方法,并进一步修改欧洲钢结构设计规范的计算公式,以适用于计算Q460高强度钢材等边箱形短柱的极限应力。

EXPERIMENTAL STUDY ON LOCAL BUCKLING OF HIGH STRENGTH STEEL SQUARE BOX SECTION STUB COLUMNS UNDER AXIAL COMPRESSION

Aiming at the local buckling behavior of high strength steel welded box section columns,four axial compression tests of Q460 square box section stub columns were conducted.Based on the test results,the relation of buckling stress and ultimate stress of specimens with different width-to-thickness ratios were studied.Besides,test results were compared with the corresponding design methods and calculation formulae in Chinese,American,European steel structures design codes and method proposed by Chen Shaofan.The research work showed that the effective areas decreased and the post-buckling strength increased with width-to-thickness ratios;the value of the buckling stress of square box section stub columns in the Chinese steel structures design code was unreasonable;the calculation results of the American,European steel structures design codes and the design method proposed by Chen Shaofan were close,which were all little higher than the test results,so all the design methods were reasonable.A new design method was proposed to predict buckling stress of Q460 square box section stub columns,which was in need of revision;the design method proposed by Chen Shaofan and the calculating formula of Eurocode 3,which was in need of revision,were recommended to predict ultimate stress of Q460 square box section stub columns.