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 reinforced concrete slab inside a building is to be designed as a 1.0 m stripe with members. The floor slab is uniaxially spanned and runs through two spans. The slab is fixed on masonry walls with free-rotating supports. The middle support has a width of 240 mm and the two edge supports have a width of 120 mm. The two spans are subjected to an imposed load of category C: congregation areas.
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.
A strut with a circular cross-section is supported according to four basic cases of Euler buckling and subjected to pressure force. Determine the critical load.
A symmetrical shallow structure is made of eight equal truss members, which are embedded into hinge supports. The structure is loaded by a concentrated force and alternatively by imposed nodal deformation over the critical limit point when the snap-through occurs. Imposed nodal deformation is used in RFEM 5 and RSTAB 8 to obtain the full equilibrium path of the snap-through. The self-weight is neglected in this example. Determine the relationship between the actual loading force and the deflection, considering large deformation analysis. Evaluate the load factor at the given deflections.
A structure is made of four truss members, which are embedded into hinge supports. The structure is loaded by a concentrated force and alternatively by imposed nodal deformation over the critical limit point, when snap-through occurs. Imposed nodal deformation is used in RFEM 5 and RSTAB 8 to obtain the full equilibrium path of the snap-through. The self-weight is neglected in this example. Determine the relationship between the actual loading force and the deflection, considering large deformation analysis. Evaluate the load factor at given deflections.
A column is composed of a concrete section (rectangle 100/200) and a steel section (profile I 200). It is subjected to pressure force. Determine the critical load and corresponding load factor. The theoretical solution is based on the buckling of a simple beam. In this case, two regions have to be taken into account due to different moments of inertia and material properties.
A thin circular ring of a rectangular cross-section is exposed to external pressure. Determine the critical load and corresponding load factor for in-plane buckling.
A cantilever beam with an I-beam cross-section of length L is defined. The beam has five mass points with masses m acting in the X-direction. The self-weight is neglected. The frequencies, mode shapes, and equivalent loads of this 5-DOF system are analytically calculated and compared with the results from RSTAB and RFEM.
Determine the torsional constant for the cross-section of the tube (annular area) analytically, and compare the results with the numerical solution in RFEM 5 and RSTAB 8 for various wall thicknesses.
A steel beam with a square cross-section is loaded with an axial force and distributed loading. The image shows the calculation of the maximum bending deflection and critical load factor according to the second-order analysis.
An axially loaded steel beam with a square cross-section is pinned at one end and spring-supported at the other. Two cases with different spring stiffnesses are considered. The verification example solves the calculation of the load factors of the beam in the image using the linear stability analysis.