受压T肋加劲板翼缘的局部稳定性能

为研究T形肋加劲板翼缘的受压局部稳定性能，考虑翼缘宽厚比的变化，设计制作5个Q345和4个Q420钢材强度的焊接T形肋加劲板试件进行翼缘局部稳定轴压试验，并建立有限元模型进行验证，分析不同材料本构、简化焊接残余应力、局部初始几何缺陷对其受力性能的影响，得到翼缘局部稳定简化计算公式。结果表明：翼缘局部稳定试件与有限元模型均在翼缘1/2高度附近发生局部屈曲破坏，翼缘宽厚比越大，试件出现局部屈曲变形越早。有限元计算模型采用理想弹塑性本构模型模拟，随着翼缘相对宽厚比增大，残余应力的计入降低了构件轴向刚度；所有板件均计入局部初始缺陷时的稳定系数最小。采用三次多项式拟合的翼缘局部稳定简化公式曲线与欧洲规范曲线的趋势较为接近，而采用Perry公式拟合的曲线与中国、美国规范曲线的趋势较为接近。不同钢材强度拟合的公式曲线趋势基本一致，可以推荐采用Perry公式拟合的曲线进行计算。

Local stability of flange of T-rib stiffened plates under compression

In order to examine the flange local stability of T-rib stiffened plates under compression, considering the variation of flange width thickness ratio, T-rib stiffened plates with Q345 strength (5 pieces) and Q420 strength (4 pieces) were fabricated to carry out the local stability axial compression test, and the finite element (FE) models were established to compare with the test. The influence of different material constitutions, simplified welding residual stresses and local initial geometric imperfections on the mechanical properties of the flange were analyzed. The simplified calculation formula for the local stability of the flange was obtained. The results show that both the test and the FE model are subjected to the local buckling failure near the flange height of 1/2, and the larger the flange width-thickness ratio is, the earlier the specimen comes to local buckling failure. The FE models are simulated by an ideal elastic-plastic constitutive model. With increase of the relative flange width-thickness ratio, the axial stiffness of the component decrease because of the inclusion of residual stress. The coefficient of stability is smallest when local initial imperfections are included. The curve of the simplified formula for the flange local stability fitted by cubic polynomial is close to the trend of the Eurocode curve, while the curve fitted by Perry formula is close to the trend of the Chinese and American standard curves. The trend of formula curves fitted with different steel strengthes is basically the same, which can be calculated by Perry formula for a safer result.