门式刚架Г型节点有限元分析

利用ANSYS软件对三种节点进行了低周往复加载和单调加载的对比分析，三种节点包括梁柱常规螺栓端板竖放节点圆弧形整体式节点和圆弧形加腋螺栓端板竖放节点。其结果表明圆弧形整体式节点和加腋改造后的节点要比常规螺栓端板连接节点刚度大，极限承载力高。加腋可缓解节点域应力的过分集中，避免了节点域的脆性破坏。圆弧形整体式节点域为圆弧形，使得该节点受力流畅，加载到破坏阶段，节点域变形较小。圆弧形加腋节点具有便于螺栓安装，节点为栓焊连接，刚度大延性也较好。同时加腋构成了第二道防线，进一步防止了偶然荷载作用下试件脆性破坏的发生。圆弧形整体式节点和圆弧形加腋节点均以梁端位移过大作为破坏准则，这三种节点的对比研究对工程设计有较好的指导意义。对于常规螺栓端板连接节点其节点域剪切变形较大，易引起节点的脆性破坏。剪切变形加大了梁端位移，且由于节点刚度相对较小，节点域应力较为集中，发生了荷载作用下柱翼缘的屈服破坏。

Finite Element Analysis on Connections in Steel Portal Frames

Three kinds of connection of the beam and column in gable portal frame were analysed by software ANSYS.The connections include the bolted end-plate connections and the whole connections and appending a armpit in the connection.They were given repeating and monotone increasing loads.The result reveals that the improving structure and the whole portal frame are better than the common structure on load capacity.The shearing deformation is smaller than the common connections,They restrict the displacement of the end of the beams and can be burden more loads than the common structure.The improving structure make a change by appending a armpit in the connection of the beam and column,The armpit is simple and is welded in the beam and column.It forms another line of defence when the accidental happened and avoids brittle failure.Then make a comparison analysis between the three models then draw a conclusion from the result,The stiffness of the improving structure is very high.It relieves the stress concentration of the connection,which can improve the ductility performance of connection to a certain,The reason for the destructive style of the second and third components are the displacement too large and the first is the flage of the column yielding failure.