Linear analysis

advanced examples

The test model is non-linear as the spring has a variable stiffness. This model can be linearized at two different operating points. Using the ameloadj and amebode scripts, the eigenvalues and frequency response functions can be computed at each operating point.

In Simcenter Amesim, replace the 1-port rotary load with a 2-port rotary load and save it as scrdemo2:

Figure 21: Parameter values

Note

Simcenter Amesim Run users can get this system through Help > Get demo, from the Tutorials directory. The file is called scrdemo2.ame.

Procedure

1. In Parameter mode, select the FX00 component and set its expression in terms of the input x to abs (x). Set the value of the shaft speed in MECRL0A-1 to 100 rev/min.

2. In Simulation mode, select Linear analysis mode and add the following linearization times:

0 seconds

0.04 seconds

Figure 22: Linearization times

3. Open the MECRL0A-1 variable list and assign the following linear analysis status:

torque at port 1: control

shaft angle at port 2: state observer

Figure 23: LA status

4. Select the File > Write files for simulation menu item to update the parameters.