Scaffolding and Rack Structures

Both the determination of natural vibrations and the response spectrum analysis are always performed on a linear system. If nonlinearities exist in the system, they are linearized and thus not taken into account. They are caused by, for example, tension members, nonlinear supports, or nonlinear hinges. This article shows how you can handle them in a dynamic analysis.

In RFEM 6 it is possible to save selected objects (as well as whole structures) as blocks and reuse them in other models. Three types of blocks can be distinguished: non-parameterized, parameterized, and dynamic blocks (via JavaScript). This article will focus on the first block type (non-parameterized).

Not all structural elements of a real building are included in a structural model. As an example, we can look at a pipe that runs along a steel girder frame.

After activating the RF‑PIPING add‑on module, a new toolbar is available in RFEM and the project navigator and tables are extended. The piping system is now modeled in the same way as the members. Pipe bends are defined simultaneously by tangents (straight pipe sections) and radius. Thus, it is easy to subsequently change bend parameters.

It is also possible to extend the piping subsequently by defining special components (expansion joints, valves, and others). The implemented libraries of structural components facilitate the definition.

Continuous pipe sections are defined as sets of piping systems.
For piping loads, member loads are assigned to the respective load cases. The combination of loads is included in piping load combinations and result combinations.
After the calculation, you can display deformations, member internal forces, and support forces graphically or in tables.

Pipe stress analysis according to standards can then be performed in the RF‑PIPING Design add‑on module. You only need to select the relevant sets of piping systems and load situations.

In SHAPE-THIN 8, the effective cross-section of stiffened buckling panels can be calculated according to EN 1993-1-5, Cl. 4.5.

The critical buckling stress is calculated according to EN 1993-1-5, Annex A.1 for buckling panels with at least 3 longitudinal stiffeners, or according to EN 1993-1-5, Annex A.2 for buckling panels with one or two stiffeners in the compression zone. The design for torsional buckling safety is also performed.

After modeling piping systems in RFEM using RF‑PIPING and defining loads as well as load and result combinations, you can carry out pipe stress analysis in the RF‑PIPING Design add‑on module.

You can select all or only some pipelines and loads, load or result combinations for piping design. The material library provides various materials according to EN 13480‑3, ASME B31.1‑2012, and ASME B31.3‑2012 standards.

After the calculation, the results are displayed in clearly arranged windows; for example, by cross‑section, by pipeline, or by members. You can also display the design ratio graphically on the entire model in RFEM. This way, you can quickly recognize critical or oversized areas of the cross-section.

In addition to the input and result data, including design details displayed in tables, you can add all graphics into the printout report. This way, comprehensible and clearly arranged documentation is guaranteed. You can select the report contents and extent specifically for the individual designs.