冷弯薄壁槽形截面钢柱的优化设计

Optimal Design of Cold formed Channel Sections

求解冷弯开口薄壁截面短柱的极限承载力是一个板组结构的大挠度弹塑性分析问题，板件之间相互作用和纵向面内加载方式对其局部屈曲后性能和稳定极限承载力有很大的影响。本文应用大挠度弹塑性有限条分析方法系统地研究了冷弯薄壁槽形截面柱的极限承载能力和它们的优化性能，并对荷载偏心距为常数和位移梯度为常数的两种加载条件下的薄壁开口短柱局部屈曲后性能和极限承载力进行了对比分析和探讨。

A theoretical investigation is presented on the prediction of ultimate load carrying capacity of a cold formed thin walled channel section with post local buckling interaction between plate elements forming the section in the inelastic range. The initial deflection of the plate elements, curvature effect on the corners of section, and cold formed strain hardening effect are considered in the analysis. A comparison is made between a constant load eccentricity and a constant compression eccentricity in post local buckling range. Differences of ultimate strength between them are obvious for a larger section ratio of flange to web width (bf/bw). The optimal load eccentricity and optimal section ratio in the case of the constant load eccentricity are presented, which are useful in the design of cold formed thin walled channel sections.