偏心受压冷弯薄壁槽钢的卷边角度优化设计
Optimization on angle of lip of cold-formed thin-walled channel under eccentric compression

为了使得钢结构的性能与用钢量比达到最优，前人对槽型钢的截面尺寸优化进行了较为充分的研究。但是，涉及卷边角度的优化特别是偏心受压工况下的优化分析却很缺乏。以Yao-Teng偏心受压计算公式，结合遗传算法，以冷弯卷边槽钢柱偏心受压为例，将槽钢卷边角度与偏心距作为设计变量，寻找在不同偏心距受压情况下，达到最大畸变屈曲临界应力的卷边角度。基于有限条分析程序，对两端简支与两端固支情况下不同截面尺寸构件的畸变屈曲临界应力进行了计算分析，最终得出不同偏心距受压下统一的最优卷边角度。为了方便工程设计人员设计时参考，建议卷边角度统一取为100°。
The optimization of the sectional dimensions is studied to make the ratio between performance and steel amount of steel sections become optimal. However, the optimization analysis of lip angle involving the eccentric compression is lack. A technique with the genetic algorithm and formulae for predicting the distortional critical stresses of cold-formed lipped channels subjected to eccentric compression is developed to optimize the angles of lips of channels. The cold-formed lipped channel columns under eccentric compressing have been taken as examples. The genetic algorithm regards the angle of lip and eccentric distance as design parameters. This method not only can decrease workload and aimless calculation but also can obtain accurate optimal angles. The distortional critical stresses of cold-formed lipped channels with different dimensions under simply and clamped supports are obtained, based on the finite strip analyses. The optimal angles of cold-formed channel steel members with different eccentric distances are presented. For designer's convenience of design and application, the degree of 100 is suggested.