冷弯薄壁帽型截面立柱轴压试验研究

EXPERIMENTAL RESEARCH OF AXIAL COMPRESSION TEST OF COLD-FORMED HAT-SECTION STEEL COLUMN

对厚度分别为0.8,1.0,1.2,1.5,1.8,2.0 mm,长度为3 m的18个冷弯薄壁帽型截面立柱进行轴压试验,并采用国内外规范及理论计算方法对立柱轴压承载力进行计算和比较。研究表明:当帽型截面的厚度较小(0.8,1.0 mm)时,立柱先局部失稳,而后发生整体弯曲或弯扭失稳;而当截面厚度较大(1.2,1.5,1.8,2.0 mm)时,立柱则直接发生整体的弯曲或弯扭失稳。采用AISI S100-2007中直接强度法计算出的帽型截面轴压承载力与试验值总体接近;当厚度为1.5,1.8 mm时,采用GB 50018—2002、AISI S100-2007和BS EN1993-1-3∶2006的计算结果与试验值吻合良好;当厚度为1.0,2.0 mm时,除BS EN1993-1-3∶2006外,中国、美国标准计算结果与试验值相差均较大,达到10%~21%。

Axial compression tests were conducted for 18 cold-formed hat-section steel columns with length of 3meters and thickness of 0. 8,1. 0,1. 2,1. 5,1. 8 and 2. 0 mm. The axial compression loading capacities of the columns were calculated based on the domestic and overseas specifications and theoretical methods,whose results were compared with the testing results. The research results showed that when the thickness was small（ 0. 8 and 1. 0mm）,the column would locally buckle first,and then overall bending or flexural-torsional buckling occurred. When the thickness was large（ 1. 2,1. 5,1. 8 and 2. 0 mm）,the overall bending or flexural-torsional buckling would occur in the column. The axial compression bearing capacity calculated by DSM in AISI S100-2007 was close to test results. When the thickness was 1. 5 and 1. 8 mm, the calculation results were in good agreement with the experimental value based on GB 50018—2002,AISI S100-2007 and BS EN1993-1-3∶ 2006. When the thickness was 1. 0 and 2. 0 mm,the calculation results had 10% ~ 21% difference with the experimental value based on Chinese and North Ameriean specifications and theoretical method except European specification.