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RF-/DYNAM Pro - Natural Vibrations Add-on Module for RFEM/RSTAB
Analysis of Natural Vibrations
The RF-/DYNAM Pro - Natural Vibrations add‑on module allows quick and comfortable analysis of natural frequencies and mode shapes of member, surface, and solid models.
All required input values can be imported directly from RFEM/RSTAB. There are four powerful eigenvalue solvers (for example Lanczos, subspace and ICG iteration) available for determination of up to 9,999 eigenvalues.
- Automatic consideration of masses from self-weight
- Direct import of masses from load cases or load combinations
- Optional definition of additional masses (nodal, linear, surface masses, as well as inertia masses)
- Combination of masses in different mass cases and mass combinations
- Preset combination coefficients according to EC 8
- Optional import of normal force distributions (in order to consider prestress, for example)
- Stiffness modification (for example, deactivated members or stiffnesses can be imported from RF-/CONCRETE)
- Consideration of failed supports or members
- Definition of several natural vibration cases (for example to analyze different masses or stiffness modifications)
- Results of eigenvalue, angular frequency, natural frequency and period
- Determination of mode shapes and masses in nodes or FE mesh points
- Results of modal masses, effective modal masses, and modal mass factors
- Visualization and animation of mode shapes
- Various scaling options for mode shapes
- Documentation of numerical and graphical results in the printout report
Input windows require all data necessary for determination of natural frequencies, such as mass shapes and eigenvalue solvers.
The RF-/DYNAM Pro - Natural Vibrations add-on module determines the lowest eigenvalues of the structure. You can adjust the number of eigenvalues. Masses are directly imported from load cases or load combinations (with optional consideration of total masses or a load component in the direction of gravity).
Additional masses can be defined manually at nodes, lines, members, or surfaces. Furthermore, you can influence the stiffness matrix by importing normal forces or stiffness modifications of a load case or a load combination.
CalculationThe RF-DYNAM Pro - Natural Vibrations module for RFEM provides four powerful eigenvalue solvers:
- Root of the characteristic polynomial
- Lanczos method
- Subspace iteration
- ICG iteration method (Incomplete Conjugate Gradient)
- Subspace iteration
- Shifted inverse iteration
The selection of the eigenvalue solver depends primarily on the model size.
After the calculation, the module displays a list of eigenvalues, natural frequencies, and eigenperiods in result windows integrated in the main program RFEM/RSTAB. The mode shapes of the structure are included in tables and can be displayed graphically or as an animation.
All result tables and graphics are part of the RFEM/RSTAB printout report. In this way, clearly arranged documentation is ensured. In addition, it is possible to export the tables to MS Excel.
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