The flexural behaviour of cold-formed ferritic stainless steel (CFFSS) closed built-up beam composed of lipped channel sections orientated face to face was examined numerically, using a finite element (FE) package ABAQUS. The developed FE models were first validated against the experimental data collected from the literature before performing the desired parametric study. Thirteen different sections were analysed, with varying plate slenderness, using two different material grades (EN 1.4003, EN 1.4509) with three different material properties and wall thicknesses. The simply supported built-up closed beams were analysed under four-point bending. The moment capacity of the built-up beams dropped with the increase in the compression flange’s plate slenderness. The pool of numerical strengths was used to assess the current DSM’s appropriateness, proposed DSM for cold-formed steel closed built-up beams, and proposed DSM for ferritic stainless steel hollow beams. Based on the above-stated strength comparisons, suitable modifications were proposed for the current DSM specifications, mainly targetting CFFSS closed built-up beams made of lipped channel sections (typically failing by local buckling). Lastly, a reliability analysis was performed to check the reliability of the current and proposed DSM specifications for CFFSS closed built-up beams.

使用有限元（FE）封装ABAQUS，以数值方式检查了冷弯的铁素体不锈钢（CFFSS）封闭的组合梁（由面对面定向的唇形通道截面组成）的挠曲行为。在进行所需的参数研究之前，首先根据从文献中收集到的实验数据对开发的有限元模型进行验证。使用具有三种不同材料特性和壁厚的两种不同材料等级（EN 1.4003，EN 1.4509）分析了十三种不同的截面，具有不同的板细长度。在四点弯曲下分析了简单支撑的组合封闭梁。随着压缩翼缘板的细长度的增加，组合梁的弯矩承载力下降。数字强度池用于评估当前DSM的适用性，提出了用于冷弯型钢封闭组合梁的DSM，并提出了用于铁素体不锈钢空心梁的DSM。基于上述强度比较，对当前的DSM规范提出了适当的修改，主要针对由唇形通道部分制成的CFFSS封闭组合梁（通常会因局部屈曲而失效）。最后，进行了可靠性分析，以检查当前和提议的CFFSS封闭组合梁的DSM规范的可靠性。