不同管径钢管带颈法兰连接受拉性能试验及有限元分析

Experimental study and finite element analysis on tensile capacity of high-neck flange of steel tube tower

针对4组共12个足尺Q345不等管径带颈法兰连接节点进行了轴心受拉和偏心受拉试验,研究不等管径对接的带颈法兰在不同强度级差匹配时的受拉性能。结果表明,各组试件的变形形态和破坏机制基本一致,法兰试件的变形主要集中在小管径一侧;试验中未发生法兰和对接焊缝的破坏;试件的承载力达到1.5倍设计承载力,具有足够安全裕度;偏心受力会一定程度地降低试件的承载能力,但其影响仅在6%左右;不同强度级别相匹配的法兰试件承载性能均表现良好;近焊缝处法兰颈口受焊接残余应力的影响较大,建议法兰与钢管对接须满足一级焊缝要求。针对法兰试件的承载力进行了非线性有限元分析,结果表明有限元分析与试验规律吻合较好。

The axial tension and eccentric tension tests of four sets of full-scale Q345 high-neck flange joints with unequal diameter tubes were carried out, and the tensile properties of unequal diameter high-neck flange joints with different strength grades were studied. The results show that the deformation pattern and failure mechanism of each specimen are consistent, and the deformation of the flange joint is concentrated on the steel tube of smaller diameter. The failure of the flange and the butt weld is not visible. The bearing capacity of the specimen is up to 1.5 times of the design value, which shows enough safety. Eccentric load reduces the bearing capacity of the specimen, but the effect is only about 6%. The flange joints with different strength grades works well. The edge of flange neck near welding line is affected by residual stress. It’s suggested that the welding line between flange and tube should satisfy first level. Based on the nonlinear finite element analysis, the bearing capacity of the flange is studied. It shows that the results of finite element analysis and experimental study are consistent.