When a beam with variable cross-section dimensions is divided retroactively, the dimensions for the beam start and beam end can no longer be modified easily. Due to the resulting intermediate nodes, a new cross-section would have to be calculated for every member segment. In order for you to not have to do this manually, it is recommended to delete the members. In doing so, take care to only delete the selected members and not their nodes. The new member can subsequently be modelled from beam start to beam end and connected to the intermediate nodes with the "Connect Members" tool.
Summary (see Figure 1):
1. Delete members (nodes must remain unchanged)
2. Insert new member from beam start to beam end
3. Connect member with intermediate nodes
In RSTAB, the members always have to be connected to each other in a node.
This is not absolutely necessary in RFEM, because it allows a node to lie on a line without dividing the member (see Figure 2). It is therefore sufficient to modify the cross-section at the beam start and beam end. If the intermediate nodes (which members already connect to) already exist and you wish to create the tapered member retroactively in RFEM, it is recommended to deactivate the option "Auto Connect Lines/Members" (see Figure 3). Afterwards the member can be created without divisions at the intermediate nodes.
variable cross-section, taper, tapered member, cross-section depth, interpolation