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.
In this verification example, the capacity design values of shear forces on beams are calculated in accordance with EN 1998-1, 5.4.2.2 and 5.5.2.1 as well as the capacity design values of columns in flexure in accordance with 5.2.3.3(2). The system consists of a two span reinforced concrete beam with a span length of 5.50m. The beam is part of a frame system. The results obtained are compared with those in [1].
Determine the required strengths and effective length factors for the ASTM A992 material columns in the moment frame shown in Figure 1 for the maximum gravity load combination, using LRFD and ASD.
A reinforced concrete column is designed for ULS at normal temperature according to DIN EN 1992-1-1/NA/A1:2015, based on 1990-1-1/NA/A1:2012-08. The design employs the nominal curvature method; see DIN EN 1992-1-1, Section 5.8.8. The addressed column is located at the edge of a 3-span frame structure, which consists of 4 cantilever columns and 3 individual trusses hinged to them. The column is subjected to the vertical force of the precast truss, snow and wind. The results are compared with the literature.
A curved frame called Lee's frame is pinned at the end points and loaded by a concentrated force at point A. Determine the deflection ratio at point A in the given load steps. The problem is defined according to The NAFEMS Non-Linear Benchmarks.
Determine the required strengths and effective length factors for the ASTM A992 material columns in the moment frame shown in Figure 1 for the maximum gravity load combination, using LRFD and ASD.
A two‑story, single‑bay frame structure is subjected to earthquake loading. The modulus of elasticity and cross‑section of the frame beams are much larger than those of the columns, so the beams can be considered rigid. The elastic response spectrum is given by the standard SIA 261/1:2003. Neglecting self-weight and assuming the lumped masses are at the floor levels, determine the natural frequencies of the structure. For each frequency obtained, specify the standardized displacements of the floors as well as equivalent forces generated using the elastic response spectrum according to the standard SIA 261/1.2003.