格构式钢管砼风力发电塔架包裹球板分支节点屈服机制研究

Study on yield mechanism of spherical plate branch joints inlattice concrete-filled steel tube wind turret

为了研究格构式钢管砼风力发电塔架包裹球板分支节点的屈服机制,进行了4个万向球板节点模型的静力试验;并采用ABAQUS对试件进行了非线性分析,通过变化包裹体径厚比和节点板厚度2个参数,对球板节点的破坏模式、节点板等效应力及节点交汇区等效应力分布规律等指标进行了分析。结果表明:万向球板节点的破坏主要由节点板连接焊缝强度破坏与压杆失稳而引起;节点板厚度的差异对万向球板节点的承载力影响较为明显,而包裹体径厚比的变化对万向球板节点的承载力影响并不明显;节点板越厚等效应力的分布越均匀;当包裹体径厚比小于等于38.5时,节点的承载力随着γ的增大下降幅度逐渐增大;当径厚比大于38.5时,节点的承载力随着径厚比的增大下降幅度逐渐较小,建议包裹体径厚比取值为38.5;节点板厚度小于等于14 mm时,极限承载力随节点板厚度的增加,其增加的幅度较大;当节点板厚度大于14 mm时,节点的承载力随厚度的增加,其增加幅度逐步减小,建议节点板厚度取值为14 mm。

In order to study the yield mechanism of branched spherical plate joints wrapped in lattice concrete filled steel tubular wind power tower,static load experiment was conducted on 4 full-scale models of CFST universal joints.Then,software ABAQUS was used for non-linear finite element analysis.By changing the radius-thickness ratio of the inclusion,thickness of gusset plats,the failure mode of joints and the equivalent stress of gusset plates and the equivalent stress of joints intersection area were analyzed.The results indicate that the damage of the universal joint was caused by the failure of the weld failure between gusset plate and steel ball and buckling of compressive bar.The bearing capacity of the universal joint is sensitive to the thickness of the gusset plat,but it is weak sensitive to the radius-thickness ratio of the inclusion.The thicker the nodal plate,the better the dissipation of the equivalent force;when the radius-thickness ratio of the inclusion is no more than 38.5(γ<38.5),the bearing capacity of joints decreases large amplitude with the increase ofγ;when the radius-thickness ratio of the inclusion is greater than 38.5,the bearing capacity of joints decreases small amplitude with the increase ofγ.It is suggested that the radius-thickness ratio of the inclusion is 38.5;when the thickness of the joint plate is no more than 14,the bearing capacity of joints increase large amplitude with the increase of n,when the thickness of the joint pate is greater than 14,the bearing capacity of joints increase small with the increase of n.