Question:
How is the buckling load determined in RSBUCK if the most unfavorable value is transferred from RSTAB for a non-constant axial force distribution?
Answer:
Basically, the buckling load is determined as follows when activating the option to transfer the most unfavorable value of the axial force for a non-constant distribution:
Critical load factor * most unfavorable value of the axial force = buckling load
However, the most unfavorable value refers to the member part, not to the entire member. The value of the most unfavorable axial force of the entire member is only assumed as the most unfavorable value if "1" is selected for "Internal Member Partition for"; see Image 01.
Otherwise, the mean value is first determined internally from the most unfavorable values of the respective member partitions. The following diagram shows the most unfavorable value for two member parts from the axial force distribution in the following image:
(60 kN + 30 kN) / 2 = 45 kN
Thus, the following buckling load results for the first buckling mode in this example:
2.429 * 45 kN = 109.3 kN