Reduced system#
Reduced system of the original one. Change the name of the system here. A * in front of the systems name indicates that the system is not up-to-date and needs to be updated. The calculation can be done without an up-to-date system. Physics type shows if it is a mechanical or thermal system.
Properties#
Number of DOFs: Number of independent movements, which describe the system. A rigid body has 6 degrees of freedom (Translation in x-,y- and z-direction, rotation around the x-,y- and z-axis).
For the reduced system, there should be a smaller number of DOFs compared to the original system.
Model reduction parameters#
Two modes can be selected:
Error limit mode#
This is the default mode. The following settings can be chosen.
Property |
Definition |
|---|---|
Frequency range of interest |
Under this frequency the relative error does not exceed the maximum relative error. |
Maximum relative error |
The number of considerate modes is selected so that the maximum error is not exceeded in the frequency range of interest. This is calculated by menas of an error estimator. |
Guessed number of modes |
Guess the number of modes to be considered. |
Maximum number of modes |
Limit the modes to be included in the reduced system. |
Stiffness scaling |
Stiffness proportional damping coefficient, multiplies stiffness matrix. |
Mass scaling |
Mass proportional damping coefficient, multiplies mass matrix. |
Manual mode#
This is the advanced mode. The following settings can be chosen.
Property |
Definition |
|---|---|
Maximum eigenfrequency |
Frequency of the last mode included in the reduced system. |
Maximum relative error |
Maximum relative error between the reduced and original system according to the error estimator. |
Maximum number of modes |
Maximum number of modes included in the reduced system. |
Expansion point |
Expansion points for the Krylov approximation. |
Stiffness scaling |
Stiffness proportional damping coefficient, multiplies stiffness matrix. |
Mass scaling |
Mass proportional damping coefficient, multiplies mass matrix. |
Numerical tolerance |
Used for the orthogonalization vectors and eigenvalue problem. |