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.
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.
A cylinder made of elasto-plastic soil is subjected to triaxial test conditions. Neglecting the self-weight, the goal is to determine the limit vertical stress for shear stress failure. An initial hydrostatic stress of 100 kPa is considered.
The settlements of a rigid square foundation on a lacustrine clay [1] are calculated with RFEM. One quarter of the foundation is modelled. The foundation has a width of 75.0 m in both sides. Construction stages are used to generate the results.