冷弯薄壁箱形截面柱在偏心荷载作用下的弹塑性屈曲

本文对冷弯薄壁箱形截面柱分别在常位移梯度偏心加载和常荷载偏心距加载下的弹塑性屈曲后性能进行了全过程屈曲分析。分析中考虑了壁板初曲、截面弯角处冷作硬化以及应力应变曲线的圆滑过渡过柱屈曲后承载能力的影响。采用修正的Ilyushin屈服准则,将线性有限条理论推广应用于解决大挠度、弹塑性稳定问题,不仅大大地减少了计算工作量,而且具有较高的精度。进行了冷弯箱形截面柱的受压试验。试验与理论分析结果比较吻合。

STABILITY IN THE ELASTO-PLASTIC RANGE OF COLD-FORMED THIN-WALLED BOX SECTIONS SUBJECTED TO AN ECCENTRICAL LOAD

The finite strip method is extended to include the nonlinearities for the material and geometry of initially deflected box sections under a constant compression eccentricity and a constant load eccentricity, respectively. The effect of enhancing of yield stress in corners of the cross—section due to coldworking and the behariour of smooth transition of stress—strain curves from elastic to plastic range on collapse load of box sections is taken into account in post—buckling range. A test programme of compressive box sections was carried out and the comparison of experimental with theoretical results shows a good agreement.