We provide hints and tips to help you get started with the RFEM program.
KB 001657 | Steady-State Solution for Periodically Excited Structures
First Steps with RFEM
By means of the modal analysis in the DYNAM Pro - Forced Vibrations add-on module it is possible to determine the steady-state for periodically excited structures. This is an advantage if only the structure's steady state is of interest. Instead of the complete solution of the equation of motion, only the special solution is displayed.
Do you have any questions about our products or need advice on selecting the products needed for your projects?
Contact us via our free e-mail, chat, or forum support or find various suggested solutions and useful tips on our FAQ page.
Models to Download
Knowledge Base Articles
By means of the modal analysis in the DYNAM Pro - Forced Vibrations add-on module it is possible to determine the steady-state for periodically excited structures.
Product Features Articles
Calculation with consideration of a damping ratio (or Lehr's damping) is not possible in the direct time step integrations. Instead, the Rayleigh damping coefficients must be specified by the user.
In technical literature, the given damping ratio for specific construction forms is in many cases only a rough approximation of the real damping ratios. In RF-/DYNAM Pro - Forced Vibrations, it is possible to use the value of damping ratio to determine the Rayleigh damping. This may occur at one or two natural angular frequencies defined by the user.
Frequently Asked Questions (FAQ)
- I would like to design an aluminum or lightweight structure. Is it possible to use RFEM or RSTAB for this?
- I have used the RF‑/DYNAM Pro add-on module to generate the governing result combinations of seismic loads. What is the next procedure to perform the design of the individual structural components?
- In RF‑/DYNAM Pro, the "From self-weight of structure" option is available in a mass case. Is it always necessary to activate this option in order to consider the dead load of the structure?
- How can I consider prestressed cables in RF‑/DYNAM Pro?
- Which programs can I use to calculate and design power plants?
- I noticed deviations from the map of DIN EN 1998‑1 or DIN 4149 in the online service "<a href="https://www.dlubal.com/en/solutions/online-services/snow-load-wind-speed-and-seismic-load-maps" target="_blank">Geo-Zone Tool: Snow, Wind, and Seismic Zone Maps</a>." Can you tell me which map is current and thus governing?
- How do you distinguish between the response spectra with equivalent loads and the response spectra without equivalent loads in RFEM and RSTAB?
- Why do I only obtain the seismic loads calculated in one direction in the case of design with RF‑/DYNAM Pro?
- Are the models and presentations from Info Day 2020 freely available, and can you send them to me?
- During the check in RF‑/DYNAM Pro, I get the message "No natural vibration case or dynamic load case has been selected for the calculation." Why?
Revitalization and Extension of Supporting Structure of Stage Roof in State Playhouse Dresden, Germany