Scholarlink

<p>This study conducted experimental and finite element analyses on the distortional buckling behavior of cold-formed steel back-to-back built-up columns (CFS-BBC) after exposure to high temperatures. Experimental research included exposure of CFS-BBC to high temperatures, measuring initial geometric imperfections, shearing tests of screw fasteners after exposure to high temperatures, and axial compression tests of CFS-BBC after exposure to high temperatures. The shearing tests on screw fasteners after exposure to high temperatures show that increased temperature would reduce the initial shearing stiffness and shearing capacity by up to 78% and 48%, respectively. However, the ductility of the fasteners connecting 1.5&#xa0;mm steel was significantly improved after exposure to high temperatures. The CFS-BBC specimens failed in distortional buckling, with the ultimate load-bearing capacity increased (up to 7%) after exposure to 600&#xa0;°C, followed by a decrease (up to 20%) after exposure to 800&#xa0;°C. Subsequently, finite element models were developed and calibrated, followed by parametric analysis to investigate the behavior of CFS-BBC after exposure to high temperatures with varied distortional buckling slenderness ratio (<i>λ</i><sub>d</sub>). Results show that the load-bearing capacity after exposure to high temperatures will decrease by up to 29% after exposure to 800&#xa0;°C. Based on the experimental and parametric analysis results, a predictive formula for the reduction factor of the load-bearing capacity after exposure to high temperatures was proposed. Finally, the coefficients in the Direct Strength Method were modified to improve its accuracy.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Behavior of the Cold-Formed Steel Back-to-Back Built-Up Columns with Distortional Buckling After Exposure to High Temperatures

  • 期刊论文

  • 发表日期：

    2025年6月12日

查看全文
  • Kai Luo,
  • Jingjie Yang,
  • Fengzuo Yan,
  • Sibao Fang,
  • Jinglei Yu,
  • Haifeng Li

摘要

This study conducted experimental and finite element analyses on the distortional buckling behavior of cold-formed steel back-to-back built-up columns (CFS-BBC) after exposure to high temperatures. Experimental research included exposure of CFS-BBC to high temperatures, measuring initial geometric imperfections, shearing tests of screw fasteners after exposure to high temperatures, and axial compression tests of CFS-BBC after exposure to high temperatures. The shearing tests on screw fasteners after exposure to high temperatures show that increased temperature would reduce the initial shearing stiffness and shearing capacity by up to 78% and 48%, respectively. However, the ductility of the fasteners connecting 1.5 mm steel was significantly improved after exposure to high temperatures. The CFS-BBC specimens failed in distortional buckling, with the ultimate load-bearing capacity increased (up to 7%) after exposure to 600 °C, followed by a decrease (up to 20%) after exposure to 800 °C. Subsequently, finite element models were developed and calibrated, followed by parametric analysis to investigate the behavior of CFS-BBC after exposure to high temperatures with varied distortional buckling slenderness ratio (λd). Results show that the load-bearing capacity after exposure to high temperatures will decrease by up to 29% after exposure to 800 °C. Based on the experimental and parametric analysis results, a predictive formula for the reduction factor of the load-bearing capacity after exposure to high temperatures was proposed. Finally, the coefficients in the Direct Strength Method were modified to improve its accuracy.