How to add forced displacement or oscillation into Simscape Multibody?

I'm trying conducting oscillation analysys of multibody dynamics in Simscape Multibody.

In my model, I need to add forced displacement. The figure is an example model that I want to make. In this model, the wall is moving and its displacement is oscillating. I know how to add external force in Simscape Multibody. But what I need is forced displacement like the figure.

The below figure is a model I'm making. In this model, I want to make 'Base solid' oscillate without external force.

Please tell me how to add forced displacement.

Answer 1

[Nathan Hardenberg]

You can easily use the "Prismatic Joint"-Block, which is for purely translational movement along one axis. Just set the following options:

As Input you provide a "Sine Wave" that you configure to your needs (e.g. change phase to convert to cosine). Note that you need to convert the Simulink signal to a physical signal with the "Simulink-PS Converter" converter.

Options in the "Simulink-PS Converter" converter:

A few elaborations

Instead of using the "Spring and Damper Force"-Block you can also provide Spring Stiffness and Damping Coefficent (under Internal Mechanics) inside of the (Prismatic/Revolute) joint-Block. This can simplify your model. Since you are using a Revolute-Joint in your model I'm guessing that your drawing does not reflect the whole model, but you are rather building a real pivot of some kind. In this case using the Blocks in your configuration might already be the better solution.

[Antonio]

However, wouldn’t this generate a force to move the solid up and down, which is not physically realistic?

If we think about modeling an irregular terrain, there should be no forces and/or torques applied to translate or rotate the terrain. Right?

[Nathan Hardenberg]

@Antonio Depends on the use-case. The question was just about forcing a displacement of a wall. Thats what my solution does! Yes it generates a force, depending on the provided input. The input is set and the force gets calculated