The structural analysis software RFEM 6 is the basis of a modular software system. The main program RFEM 6 is used to define structures, materials, and loads of planar and spatial structural systems consisting of plates, walls, shells, and members. The program also allows you to create combined structures as well as to model solid and contact elements.
RSTAB 9 is a powerful analysis and design software for 3D beam, frame, or truss structure calculations, reflecting the current state of the art and helping structural engineers meet requirements in modern civil engineering.
Do you often spend too long calculating cross-sections? Dlubal Software and the RSECTION stand-alone program facilitate your work by determining section properties of various cross-sections and performing a subsequent stress analysis.
Do you always know where the wind is blowing from? From the direction of innovation, of course! With RWIND 2, you have a program at your side that uses a digital wind tunnel for the numerical simulation of wind flows. The program simulates these flows around any building geometry and determines the wind loads on the surfaces.
Are you looking for an overview of snow load zones, wind zones, and seismic zones? Then you are in the right place. Use the Geo-Zone Tool to determine quickly and efficiently snow loads, wind speeds, and seismic data according to ASCE 7‑16 and other international standards.
Would you like to try out the capabilities of the Dlubal Software programs? You have the opportunity to do so! The free 90-day full version allows you to thoroughly test all our programs.
The ASCE 7-22 standard provides several types of design spectra. In this FAQ, we would like to focus on the following two design spectra:
The two-period spectrum is implemented in the program as usual. However, based on the data available from the standard, only the horizontal design spectrum / MCER spectrum as well as the modification related to the force and displacement can be offered.
For the multi-period design spectrum, discrete numerical values are specified. ASCE 7‑22 states that these values can be queried on the USGS Seismic Design Geodatabase page. In the current state of development, you have the option to create a user-defined response spectrum with a g‑factor (depending on the mass conversion constant) to use the data from the ASCE 7 Hazard Tool [1], for example.
Please proceed as follows:
To perform an earthquake analysis, you need a modal analysis and then a load case of the Response Spectrum Analysis type.
After you have performed your modal analysis, create a new load case. Here you will find the usual settings from the previous program generation.
In the Response Spectrum tab, you can define your response spectrum as usual. If you want to use a response spectrum according to the standard, make sure that the desired standard is selected in the general data of Standards II.
In the Selection of Modes tab, you can select the mode shapes and filter them, if necessary.
After the load case has been calculated, you obtain the results.
Yes, you can also export the response spectra from RFEM 6 and import them into RFEM 5 as a user-defined response spectrum. Please note that export and import via Excel may also have different columns/descriptions due to different versions.
Export your data in RFEM 6 to Excel.
If you want to import this table directly, you will get an error message. RFEM 5 expects a different worksheet description and two columns only.
As soon as you adjust the name in Excel and delete the column with the frequency results, you will be able to edit the response spectrum in RFEM 5.
Masses can be neglected in the modal analysis settings.
It is possible to neglect masses in all fixed nodal supports and line supports, or to create a selection of the individual objects.
If no angle can be defined in the "Rotation" column, there is an isotropic material model selected for the material, where stiffnesses are identical in all directions and it is not necessary to define an angle.
If you use materials with anisotropic behavior (for example, timber), it is necessary to ensure that the "Orthotropic | Linear Elastic (Surfaces)" material model is selected.
Note: The "Orthotropic | Timber | Linear Elastic (Surfaces)" material model cannot be currently used in combination with the "Layers" thickness type.
As soon as switching to the orthotropic material model, the individual layers can be rotated accordingly.