Maksymalne stosunki b/t i h/w są określone w Tabeli 1 lub Tabeli 2, w zależności od sił wewnętrznych w prętach. For members subject to pure axial compression, Table 1 is used. For members subject to flexure or flexure+axial (beam-column), Table 2 is used.
In RFEM, the preset setting is to neglect the bending moment if the ratio is less than 1%. Therefore, the program shows “Class 4” since the check is based on Table 1.
To change this setting, go to Details and set the limit values to zero (as shown in Image 1). By doing so, the program runs the check per Table 2 and no longer ignore the small moments.
Note: In the example model, where moments are zero at the support locations, the result is still shown as “Class 4 (non-designable)”.