A structure consists of I-profile simply supported beam. The axial rotation φx is restricted on the both ends but the cross-section is free to warp (fork support). The beam has an initial imperfection in Y-direction defined as a parabolic curve with maximum displacement 30 mm in the middle. Uniform loading is applied in the middle of the top flange of I-profile. The problem is described by the following set of parameters. The verification example is based on the example introduced by Gensichen and Lumpe.
This example compares the effective lengths and critical load factor, which can be calculated in RFEM 6 using the Structure Stability add-on, with a manual calculation. The structural system is a rigid frame with two additional hinged columns. This column is loaded by vertical concentrated loads.
Verify that a beam of different cross-sections made of Alloy 6061-T6 is adequate for the required load, in accordance with the 2020 Aluminum Design Manual.
Determine the allowable axial compressive strength of a pinned 8-foot-long beam of various cross-sections made of Alloy 6061-T6 and laterally restrained to prevent buckling about its weak axis in accordance with the 2020 Aluminum Design Manual.