Question:
How does RF‑STABILITY or RSBUCK determine the buckling load? According to the manual calculation, the respective buckling loads should be about 10% higher.
Answer:
The partial safety factor γ-M for reducing the modulus of elasticity is very likely activated in RFEM/RSTAB, but is not considered in the manual calculation.
γ-M can be displayed and adjusted, if necessary, within the "Edit Material" dialog box; see Image 01.
Furthermore, the "Activate stiffness modifications from RFEM/RSTAB" option must be considered in the General Data in the RF‑STABILITY or RSBUCK add-on module; see Image 02.
For the effective length of 35.405 m, the second moment of area of 8,356 cm4, the modulus of elasticity of 21,000 kN/cm², and the partial safety factor of 1.1 as a divisor, the following buckling load results (see also Image 03) according to the following formula: