轴压钢柱局部稳定的样条函数分析法

本文采用三次混合样条构造钢柱截面板件横向位移场,假定板件平面外位移沿杆件纵向分布为解析三角函数,导出了轴压钢柱弹塑性局部稳定分析的样条函数法。分析时可计入初挠度,残余应力等初始缺陷,可精确考虑板件间相互约束作用。计算表明:本文方法精度高、速度快。

A SPLINE FUNCTION SOLUTION FOR THE LOCAL INSTABILITY OF AXIALLY LOADED STEEL COLUMNS

In this paper,the problem of the locally elasto-plastic instability of steel colu-mns under axial compression is solved by the method of spline function.In thesolution,the field of the transverse displacement of the constituting plates of thesteel column is expressed by a mixed spline function of the third order and thedistribution of the displacement deviating from the middle plane of the plates inthe longitudinal direction of the column is assumed to be varying as a trigometric function.The method of spline function is derived from the analysis of the non-linear local instability of axially loaded steel columns.In the analysis,imper-fections as the initial deflections,the residual stresses etc.all may bc taken intoconsideration and the interactive restraint effects among plates can also be consi-dered accurately.Numerical examples show that the present methed has good acc-uracy and satisfactory computational speed.