三面受火型钢混凝土柱耐火性能有限元分析

在实际火灾中,结构中的柱有可能处于三面受火状态,由于受火边界的差异,其耐火性能与四面受火的情况有所不同。在试验研究的基础上,为进一步深入认识三面受火型钢混凝土(SRC)柱的耐火性能,采用ABAQUS有限元软件建立了三面受火SRC柱的非线性有限元模型,对三面受火SRC柱的破坏过程及机理进行了数值模拟,计算结果与实验结果吻合较好。利用该模型对影响三面受火SRC柱耐火极限的主要参数荷载比及偏心率进行了分析。结果表明,对于偏心受压三面受火型钢混凝土柱,偏心率小于0.2,耐火极限随着偏心率的增加而减小;偏心率大于0.2,耐火极限随着偏心率的增加而逐渐增大。荷载比小时偏心率对耐火极限的影响更大一些,总体上偏心率的影响不是太显著。荷载比对偏心受压三面受火型钢混凝土柱有显著影响。

Theoretic analysis on behavior of steel reinforced concrete columns subjected to 3-side heating

In real fire situation,columns in structures may be heated from 3-side,which will lead to a different fire behavior comparing with 4-side heated columns.To discover the behavior of SRC columns subjected to 3-side heating,theoretic analysis was conducted in this paper,based on the foregoing experimental studies.An nonlinear finite element model using ABAQUS was set up to analyze the fire resistance of steel reinforced concrete（SRC） columns subjected to 3-sides heating.The analysis results are in good agreement with that of test.Using the model,failure mechanism and damage process were researched,and effects of main factors related to fire resistance,i.e.load ratio and eccentricity,were studied.From the results we can see,fire resistance decreases with the increasing of load eccentricity when load eccentricity is less than 0.2,but it is reverse when load eccentricity is great than 0.2.With less load ratio,influence of load eccentricity becomes more obvious.Generally speaking,load eccentricity has little influence on fire resistance.Load ratio makes great impact on fire resistance of 3-side heated SRC colulms.