摘要
实际工程中,钢管混凝土柱表面的防火涂料可能会发生局部脱落,将影响火灾下构件的温度分布,进一步影响构件的耐火极限。为获得防火涂料局部脱落的钢管混凝土柱温度分布规律,为此类构件的抗火设计提供参考,采用ABAQUS建立了涂料局部脱落构件的温度场有限元模型,分析了构件截面形状系数和长度、防火涂料厚度和热工参数、涂料脱落位置和脱落长度等对构件温度的影响。分析结果表明,圆形与方形构件的温度分布类似,前者温度略高于后者。涂料在构件两端脱落和跨中脱落的工况可根据对称性简化为一端脱落。涂料脱落仅影响沿柱长有限区域内的温度分布,随着升温时间的增大、涂料脱落长度的增大、涂料导热系数的减小、涂料厚度的增大以及构件截面形状系数的减小,该区域长度增大。
Local damage of sprayed fire protection of concrete-filled steel tubular(CFST)columns could happen in engineering practices,which may affect the temperature field and further the fire resistance of the column.To obtain the temperature distribution of CFST columns with local damage of fire protection and provide recommendations for the fire design of the locally-damaged columns,a finite element model was developed using ABAQUS.The influences of coefficient of the cross-section shape,column length,location and length of the damaged fire protection,thickness and thermal properties of the fire protection on the temperature distribution were analyzed.The development of temperature in a circular section is similar to that in a square section and the former is slightly higher than the latter.Based on geometric symmetries,the conditions in which the fire protection is damaged at two ends or mid-height of the column could be equivalent to the condition of the one-end damage.The local damage of fire protection only influences the temperature of the CFST column within a limited area.The length of the affected area increases with the increases of the heating time,the damage length,the thickness of the protection and the decreases of the thermal conductivity of the protection and the coefficient of the cross-section shape.
作者
周威
毕颖
赵磊
ZHOU Wei;BI Ying;ZHAO Lei(Hebei Vocational College of Rail Transportation,Hebei Shijiazhuang 050000,China;School of Civil Engineering,Zhengzhou University,Henan Zhengzhou 450001,China;Zhengzhou Shengda University,Henan Zhengzhou 451191,China)
出处
《消防科学与技术》
CAS
北大核心
2022年第1期41-47,75,共8页
Fire Science and Technology
基金
国家自然科学基金项目(51508523)。
关键词
钢管混凝土柱
防火涂料
局部脱落
温度场
有限元
concrete-filled steel tubular(CFST)columns
fire protection
local damage
temperature distribution
finite element
