When modeling curved members using member segments, discontinuities in the diagram of internal forces occur at the transition of the individual members due to the different inclinations of the members, as the nodal equilibrium must be fulfilled (see Image 01). If the jumps are too great, we recommend increasing the number of member segments to minimize buckling between the members. Thus, you obtain more consistent and accurate distribution of the internal forces.
In Image 02, the different variants are compared. At the top, a curved member has been modeled in RFEM and is considered a reference. Below, the variants with 150, 50, and 10 member segments (n) are displayed with the result. The finer the division of the member segments, the more accurate the result.
In the menu [Tools → Generate Model - Members → Arc], you can also generate these member segments (see Image 03).