Defining frame member joint conditions

The frame member joint conditions are defined as a data set using "Member Joint  dialog. There are only two data items, each of which represents the joint condition at one end of a frame member. It is assumed that each frame member has only two end nodes: the left and the right end node. The check mark of the check box in front of "Left end node" or "Right end node" indicates that the corresponding node is pin-jointed. The check mark is turned on and off by clicking the check box. In order to define a truss member joint, turn on both check boxes. Unchecking both of the check box makes the member joint condition with both ends rigidly jointed. Defining such a joint condition is redundant, because all the frame members are originally assumed to be rigidly jointed at both of their ends.