局部火灾作用下PEC柱组合框架抗火性能研究

Fire resistance performance of PEC columns-steel beam composite frame under local fire

应用ABAQUS软件建立局部火灾作用下PEC柱—钢梁组合平面框架的温度场和抗火性能分析模型,模型得到相关试验数据的验证。应用验证后的模型分析火灾高温下PEC柱—钢梁组合框架的失效模式、PEC柱内力变化规律和结构变形特征等,并分析火灾发生位置对PEC框架结构耐火性能的影响。结果表明:在不同的保护层厚度和荷载情况下,PEC柱—钢梁组合框架会出现梁先失效和柱先失效两种不同的失效模式;柱先失效模式会导致结构整体的破坏,梁先失效模式只会引起结构局部发生破坏;框架受火面积越大,受火柱的轴压比和受火梁的荷载比越大,框架的耐火极限越短。

By using ABAQUS program,finite element model was established to calculate the temperature field distribution in the frame members and the fire resistance behavior of PEC columns -steel beam composite plane frame under local fire condition,which was validated by some test data.The effect of fire location on the fire resistance of the frame structure,failure mode of the frame,change regulation of the internal force in the PEC column and the deformation behavior were analyzed.Base on the research work,it can be seen that columns failure mode and beam failure mode will appear when the plane frame under the different load condition and fire retardant coating thickness.Columns failure mode will lead to overall structural failure,but only local damage appeared in the beam failure mode.Main influencing factors of the fire resistance limit of the frame is axial load level of columns and beams.Increasing of loading level of the columns and beams,as well as the region exposed to fire will cause the drop of fire resistance of the frame.