Simulation and Analysis of the Results

We can isolate the spring damper component for our analysis. We then have only one power input coming from the upper port because the flux variable at the lower port is null:

The component spring damper has two internal powers, one resistive and one capacitive. Therefore, we have:

Figure 15: Power Balance [W] on the Spring Damper component

The results are consistent.

Note that as expected, the resistive power is always positive.

Now we will perform a similar test on the mass component, except we will do it in Energy [J] rather than in Power [W], assuming null integration constants (initial values).

We isolate the mass component for our analysis. The mass has two input powers; one is coming from the lower port and the other one is the implicit variation of potential gravity energy that is declared as a source S in the submodel mechanical source (grav). On the other hand, the mass has one internal kinetic energy:

Figure 16: Energy Balance [J] on the falling Mass component

As a final analysis using this model, we consider the complete system. There is then only one energy input (potential gravity energy, represented as a source S variable in the mass submodel) and the three internal energies. The energy balance equation becomes:

Figure 17: Energy Balance [J] unitary test on a Mass-Spring-Damper system

We can see that the results are as expected.

Complementary analysis can be found through the Power, Energy, Activity window, selecting the Energy tab. The values at Final time are proposed:

Figure 18: Power, Energy, Activity window - Energy Tab [J]

Next, you can follow the transfer between the different types of energies selecting all variables to get them as Bar Graphs. The animation toolbar allows you to set various times to follow their evolutions:

Figure 19: Evolution of the Energies [J] as Bar Graphs at t=0.1 s

Figure 20: Evolution of the Energies [J] as Bar Graphs at t=0.15 s