Behaviour of cold-formed stainless steel beams at elevated temperatures

A study of the behaviour of constructional cold-formed stainless steel beams at elevated temperatures was conducted in this paper. An accurate finite element model (FEM) for stainless steel beams was developed using the finite element program ABAQUS. Stainless steel beams having different cross-sections were simulated in this study. The nonlinear FEM was verified against the experimental results. Generally, the developed FEM could accurately simulate the stainless steel beams. Based on the high temperature stainless steel material test results, a parametric study was carried out on stainless steel beams at elevated tem- peratures using the verified FEM. Both high strength stainless steel EN 1.4462 and normal strength stainless steel EN 1.4301 were considered. A total of 42 stainless steel beams were simulated in the parametric study. The effect of temperatures on the behaviour of stainless steel beams was investigated. In addition, a limiting temperature for stainless steel beams was also proposed.

高温作用后新型高强QN1803不锈钢轴压构件局部稳定性能研究

通过建立新型高强度QN1803不锈钢工字形和方矩形截面短柱的有限元模型对其高温作用后的局部稳定性能进行了数值模拟分析.通过参数分析探究了残余应力、局部初始几何缺陷及温度工况对构件局部稳定性能及极限承载力的影响.研究结果表明:对于方矩形构件及截面正则化长细比小于1.0的厚实工字形构件,残余应力对承载力的影响较小;对于薄柔工字形构件,残余应力会降低其截面承载力,且降低幅度随着温度的升高而下降.此外,随着温度升高,初始几何缺陷对不锈钢工字形构件承载力产生显著影响且正则化宽厚比的影响限值变大,对不锈钢方矩形构件承载力的影响则相反.最后,本文基于参数分析结果,评估了现行欧洲规范EN 1993-1-4、美国规范ASCE/SEI-8-02以及中国《不锈钢结构技术规程》(CECS 410:2015)中不锈钢构件局部稳定性能常温设计方法的适用性,发现了现有设计方法中对高强不锈钢轴心受压构件的高温作用后设计指导尚存在不合理之处并提出了优化建议.