Modal analysis - Stiffness Matrix - Simulink vehicle suspension model

Hi to everyone! I made a 7DOF suspension vehicle model in Simulink, I need to perform a modal analysis and to do it, I have to extract stiffness mass and damping matrices somehow. Can someone give me some guidelines??

Thanks.

Mattia

[Benjamin Thompson]

Can you post the model?

[Mattia Abrate]

Of curse!

Answer 1

[Kartik Saxena]

Hi,

In order to perform a general Modal Analysis, we can follow the following guidelines:

1. Linearize Your Model

First, you need to linearize your Simulink model to obtain a linear state-space representation (A, B, C, D matrices) of the system around a specific operating point. Use the 'linmod', 'linmod2', or 'linearize' function to linearize your Simulink model.

• Linearize Simulink Models: Linear Analysis Tool
• 'linearize' function: linearize

2. Extract Mass, Damping, and Stiffness Matrices

Once you have the state-space model, you can derive the mass (M), damping (C), and stiffness (K) matrices.

• Understanding State-Space Models: State-Space Models

3. Perform Modal Analysis

With the M, C, and K matrices, you can now perform modal analysis to find the natural frequencies, damping ratios, and mode shapes.

• Modal Analysis

I hope it helps.