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.

Context Menu#

Delete#

Delete the system.

Set as default system#

Set the system as default system. The calculations are performed with this system