冷弯厚壁钢管短柱试验及规范公式比较

以宽厚比为主要变化参数,进行了16根冷弯厚壁钢管轴压短柱试验,研究冷弯效应对强度的影响.试验结果表明:荷载-位移曲线的形状主要取决于截面的宽厚比.宽厚比较小时,达到峰值荷载后下降较慢,邻近破坏时构件的轴向位移很大;宽厚比大时,局部屈曲影响明显,荷载达峰值后下降较快.同时基于试验结果,与国内外规范考虑冷弯效应的屈服强度计算公式进行了比较,认为我国规范考虑冷弯效应的屈服强度计算公式对于全截面有效的冷弯厚壁型钢也是适用的,且偏于保守.

Experimental Research on Cold Formed Thick Walled Steel Box Stubs and Comparison of Results with Related Codes

Sixteen specimens were tested under axial compression to investigate the effect of cold forming process on the behavior of stub columns. The main parameters varied in the tests were the width thickness ratio of steel tubes. The test results indicate that the shape of load displacement curves depends mainly on the width thickness ratio of cross sections. When the width thickness ratio is relatively small, the axial load decreases slowly after the peak ponit of the curve and the total axial displacement is relatively large before failure. On the contrary, the effect of local buckling on the load displacement curves is significant, which results in the sharp declining of curves after the peak point when the with thickness is rather large. Meanwhile, the calculation results of related standards considering the cold forming effects were compared with the experimental results. The comparison show that the formula for calculating the yielding strength of cold Formed thin Walled sections considering the cold forming effects in Chinese Technical Code of Cold Formed Thin Walled Steel Structures(GB50018 2002) is suitable for those cold formed thick walled steel stubs with local buckling restrained.