火源位置对轻型门式刚架竖向位移的影响

为探究总火源功率相同时,两个火源相对位置变化对轻型门式刚架竖向位移的影响规律,采用经实验验证过的有限元方法对其进行瞬态非线性热-结构耦合数值模拟,研究了大功率火灾下单个火源、两个火源位置变化对门式刚架的温度分布以及竖向位移的影响。结果表明:保持火灾总功率30 MW不变时,在单一火源作用下火源位于跨中时刚架位移最大,在两火源作用下,15 MW-15 MW的火源组合最危险、刚架的破坏时间随火源相对距离的增大而增大,功率较大的火源位于临界位置比功率较小的火源位于临界位置有利。且功率较大的火源位于临界位置时,火源相对位置变化对刚架竖向位移的影响不显著,而功率较小的火源位于临界位置时, 影响显著。

Impact of fire location on vertical displacement of light portal frame

The transient nonlinear thermal-structural coupled numerical simulation is performed by the finite element method (verified by experiments), to explore the influence of the relative position of two fire sources on the vertical displacement of light portal frame with the same total fire power. The results show that when the total fire power is kept at 30 MW, the displacement of light portal frame is the largest when the single fire source is located in the middle of the span. In addition, the most dangerous combination is 15 MW-15 MW fire source under the condition of two fire sources, and the failure time of light portal frame increases with the increase of the relative distance of the fire source. The fire source with higher power located at the critical position is more favorable than the lower power fire. The relative position of the fire sources has a significant influence on the displacement of light portal frame when the fire source with a higher power is located at the critical position, while has no significant effect when the lower power fire source is located at the critical position.