按帮助文件中所说,该单元两个节点在如果都只考虑一个方向的自由度,则两节点可以在任意位置,但重合更好,如果每个节点有二个或三个自由度,则两节点不能重合。
你可以看帮助文件里的验证手册中的VM156例子及其命令流,参考其中的建模方法。
以下是帮助文件内的说法:
*The element assumes only a 1-D action. Nodes I and J may be anywhere in space (preferably coincident)
*If you specify KEYOPT(4) ≠ 0, the element has two or three displacement degrees of freedom per node. Nodes I and J should not be coincident, since the line joining the nodes defines the direction of the force.