涂层剥落对波纹腹板组合梁抗火性能的影响

Effect of Coating Peeling on Fire Resistance of Composite Beams with Corrugated Webs

为研究涂层剥落对波纹腹板组合梁抗火性能的影响,采用ABAQUS有限元软件建立波纹腹板组合简支梁在ISO834标准升温曲线下的热分析和力学分析有限元模型,以涂层剥落位置及剥落方式为参数,分析了截面温度分布规律以及不同参数对波纹腹板组合梁抗火性能的影响差异。结果表明:组合梁在火灾中的破坏位置位于涂层剥落段,破坏特征为涂层剥落段组合梁挠曲;涂层剥落位置对波纹腹板组合梁抗火性能影响较大,当剥落位于钢梁下翼缘剪弯段或纯弯段时,组合梁耐火时间约为无剥落时的48%,而钢梁下翼缘全跨涂层剥落时,耐火时间约为无剥落时的64.5%,钢梁腹板剪弯段处涂层剥落时,耐火时间约为无剥落时的61.3%;涂层剥落方式对组合梁抗火性能影响较小,单、双侧剥落导致组合梁耐火时间相差5%~21%。

In order to study the effect of coating spalling on the fire resistance of corrugated web composite beams(CWCB),the finite element model of thermal analysis and mechanical analysis of corrugated web composite simply supported beam under ISO834 standard heating curve was established by ABAQUS finite element software.In the analysis,taking the coating peeling position and spalling method as parameters,the temperature distribution and mechanical responses of corrugated web composite beams were analyzed.The experimental results demonstrate that the failure position of CWCB in the fire is located in the coating peeling section,and the failure is due to the excessive deflection of CWCB.In addition,the peeling position of the coating influences significantly on the fire resistance performance of CWCB.When the peeling occurs in the bending area or bending-shearing area along the bottom flanges of steel beams,the fire resistance time of the composite beam is about 48%of that without peeling.When the lower flange of the steel beam is peeled off,the fire resistance time is about 64.5%of that without peeling.When the peeling of coating occurs at the web in bending segement,the fire resistance time is about 61.3%of that without peeling.Finally,the coating spalling method has little effect on the fire resistance of the composite beam.The single and double side spalling results in a 5%to 21%difference in the fire resistance time of the composite beam.