高温下不锈钢工字形截面构件局部稳定性能研究

Study on Local Stability of Stainless Steel I-sections Members at Elevated Temperatures

为研究火灾下不锈钢构件的局部稳定性能及其破坏机理,介绍了8个奥氏体型焊接工字形截面短柱的轴心受压试验,其中包括6个高温试验和2个常温对照试验.分析试验构件的失稳模态和局部稳定承载力,利用有限元模型对影响构件局部稳定性能的重要因素做了参数分析.结合试验与数值分析结果,对现有欧洲规范设计方法进行了评估.结果表明:随着温度升高,构件的刚度下降,屈曲变形增大,局部稳定承载力降低幅度增大;初始缺陷对构件承载力影响较小,截面宽厚比是影响局部承载力的关键因素;现有欧洲规范设计方法预测结果较为准确.

To study the local buckling behaviour and failure mechanism of stainless steel components in fire,axial compression tests of eight austenitic welded I-section stub columns were introduced,which included six elevated temperature tests and two room temperature reference tests.In addition,this study analyzed their instability mode and local buckling bearing capacity,meanwhile,the important influence factors on column local stability were analyzed using numerical parametric studies.The current European design method was evaluated on the basis of the experimental and numerical data.The results show that as the temperature increases,the stiffness of the specimen decreases,the buckling deformation increases and the local buckling resistance decreases;the initial imperfection has little effect on the resistance of the specimen,and the section width-thickness ratio is the key factor affecting the local buckling resistance;the predictions of the current Eurocode design method are relatively accurate.