Scholarlink

<p>Due to the high cost of full-scale high-temperature tests, scaled experiments are often used to predict the mechanical response of prototype structures. However, the heating capacity of existing furnaces fails to meet the required heating rates for models with large scaling factors. In this study, thermo-mechanical sequentially coupled simulation method is employed to investigate the similarity relationships of fire resistance performance in geometrically similar I-beams under the standard fire curve. The results indicate that: (i) According to thermal similarity theory, the time needed to reach the same temperature scales linearly with size factor, but under uniform heating curve, this relationship becomes sublinear, showing scale effect. (ii) Within load ratio range of 0.3–0.8, critical temperature does not vary with size. For every 0.1 increase in load ratio, critical temperature decreases by 40&#xa0;°C. The relationship between the fire resistance limit of geometrically similar beams and size factor can be preliminarily characterized by <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\({t}_{\lambda }/{t}_{\text{r}}={\lambda }^{0.5}\)</EquationSource> </InlineEquation>. (iii) As load ratio decreases, the heating rate attenuation in small-sized members becomes more pronounced, and the scale effect becomes more evident. (iv) Flange width and web height changes affect the fire resistance limit by less than 1%. Increasing the flange and web thickness improves fire resistance. However, when flange-to-web thickness ratio exceeds 2.6, the failure mode shifts, leading to a decrease in the fire resistance limit. This effect is more significant in larger beams. (v) A scale effect formula for the fire resistance limit of geometrically similar I-beams, considering cross-sectional size and load ratio, was established.</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

Study on the fire resistance limit scaling effect of geometrically similar I-beams under fire exposure

  • 期刊论文

  • 发表日期：

    2026年3月26日

查看全文
  • Liu Jin,
  • Yitao Gao,
  • Renbo Zhang,
  • Ningbo Fan,
  • Xiuli Du

摘要

Due to the high cost of full-scale high-temperature tests, scaled experiments are often used to predict the mechanical response of prototype structures. However, the heating capacity of existing furnaces fails to meet the required heating rates for models with large scaling factors. In this study, thermo-mechanical sequentially coupled simulation method is employed to investigate the similarity relationships of fire resistance performance in geometrically similar I-beams under the standard fire curve. The results indicate that: (i) According to thermal similarity theory, the time needed to reach the same temperature scales linearly with size factor, but under uniform heating curve, this relationship becomes sublinear, showing scale effect. (ii) Within load ratio range of 0.3–0.8, critical temperature does not vary with size. For every 0.1 increase in load ratio, critical temperature decreases by 40 °C. The relationship between the fire resistance limit of geometrically similar beams and size factor can be preliminarily characterized by \({t}_{\lambda }/{t}_{\text{r}}={\lambda }^{0.5}\) . (iii) As load ratio decreases, the heating rate attenuation in small-sized members becomes more pronounced, and the scale effect becomes more evident. (iv) Flange width and web height changes affect the fire resistance limit by less than 1%. Increasing the flange and web thickness improves fire resistance. However, when flange-to-web thickness ratio exceeds 2.6, the failure mode shifts, leading to a decrease in the fire resistance limit. This effect is more significant in larger beams. (v) A scale effect formula for the fire resistance limit of geometrically similar I-beams, considering cross-sectional size and load ratio, was established.