摘要
针对骨架式膜结构火灾下焊缝开裂引发的热烟气逸出问题,通过FDS软件建立精细化数值模型,研究焊缝开裂对温度场的动态影响机制,分析建筑几何参数、火源参数及屋面形状对结构内部温度场的影响规律。结果表明:焊缝开裂可显著降低膜面附近温度,温度峰值和稳态温度较未开裂场景分别下降13%和19%,并通过形成泄压通道抑制高温聚集;建筑几何参数、火源参数、屋面形状分别通过热烟气扩散调控、火源热释放速率与羽流空气卷吸量以及几何约束效应影响膜面附近空气温度场的分布,三者均通过改变焊缝开裂程度调节烟气逸出比例,决定结构稳态温度场特性。研究成果可为骨架式膜结构的主动防火设计提供参考。
Aiming at the problem of heat and smoke release caused by weld seam cracking in framework membrane structures during fires,a refined numerical model was constructed using FDS software to study the dynamic impact mechanism of weld seam cracking on the temperature field and further analysis was conducted on the influence of building geometric parameters,fire source parameters and roof shape on the internal temperature field of the structure.The results show that weld seam cracking can significantly reduce temperatures near the PVC coated fabrics surface,with peak temperature and steady-state temperature decreasing by 13%and 19%,respectively,compared to scenarios without cracking.This is achieved by forming pressure relief channels that suppress high-temperature accumulation.The building geometric parameters,fire source parameters and roof shape affect the distribution of air temperature field near the membrane surface through the regulation of hot smoke diffusion,the heat release rate of fire source,the air entrainment of plume and the geometric constraint effect,respectively.All of them adjust the proportion of smoke emission by changing the cracking degree of weld,and determine the steady-state temperature field characteristics of the structure.The research results can provide valuable insights for active fire protection design in framework membrane structures.
作者
杨梦姚
王平山
徐晓明
YANG Meng-yao;WANG Ping-shan;XU Xiao-ming(Arcplus Group PLC,Shanghai 200041,China;Shanghai Scientific Technology Development Branch of Arcplus Group PLC,Shanghai 200041,China;East China Architectural Design&Research Institute,Shanghai 200041,China)
出处
《河南城建学院学报》
2025年第4期56-62,116,共8页
Journal of Henan University of Urban Construction
关键词
骨架式膜结构
PVC膜材
火灾
温度场
焊缝
framework membrane structure
PVC coated fabrics
fire
temperature field
weld seam
