L形截面钢柱稳定性研究

Research on the stability of L-section steel column

L形截面钢柱用于住宅工程中能满足室内不露柱的建筑要求。L形截面无对称轴,截面剪切中心与形心不重合,易发生弯扭屈曲,目前还没有这种柱的设计计算公式,研究L形截面钢柱的稳定性具有重要的理论和现实意义。采用开口薄壁柱理论,通过任意截面钢柱弯扭相关屈曲一般方程,研究L形截面柱轴心受压,得到柱轴心受压换算长细比,并引入初始缺陷影响分析,得到任意截面钢柱在轴心压力作用下的工程实用计算公式,再用工程中H型钢拼接成的几组L形截面钢柱进行轴心受压试验,验证该公式的正确性。在此基础上,又研究了在双向压弯作用下任意截面钢柱的稳定性和工程实用计算公式,并通过几组L形截面钢柱双向压弯试验进行验证。

L-section steel column for the housing project can meet the architectural requirement that the interior columns do not reveal.But research on the stability behavior of such steel column is lack,due to the L-shaped cross-section hasn't symmetry axis,cross section shear center and centroid do not coincide,prone to flexural-torsional.In classical steel structural theory,L-section steel column belongs to abnormity-section steel column.Base on the open thin-welled theory to discuss the general equation for torsional-flexural interactive buckling of abnormity-section steel column,and then proposed the equivalent slenderness ratio of abnormity-section steel column under axis compression.Considering about the influence of initial imperfections,the practical engineering formula of abnormity-section steel column under axis compression was obtained.The experimental study of several L-section steel columns composed by H-shaped steel under axis compression proved that the practical engineering formula of abnormity-section steel column under axis compression is correct.Simplified the general equation for torsional-flexural interactive buckling of abnormity-section steel column,and then considered about the influence of initial imperfections,brought some related coefficients,the practical engineering formula of abnormity-section steel column under combined bending and torsion was obtained.The experimental study of several L-section steel columns under combined bending and torsion proved that the practical engineering formula of abnormity-section steel column under combined bending and torsion is correct.