How Can Non-Linear Friction Models Be Parameterized in MapleSim?

[maxpower2008]

Hey all,

I'm trying to develop a physical model of a mechanical system in MapleSim, and have the questions about the friction model used. This isn't a software question, but more trying to understand the math of a non-linear friction model.
The model itself is a sum of the Coulomb friction (the familiar F= uN component), as well as Stribeck and viscous effects.
As a result, the model requires input parameters such as breakaway friction force, viscous friction coeff., and transition approx. coeff.
My question is: How can I get numbers for these values? I have some performance data for my system but what do I need to know to find numbers for those input parameters? Can they only be determined experimentally?

Thanks in advance,
-Max

 

[Achy47]

Hi Max,

Thank you for your question! It's great that you're trying to develop a physical model of a mechanical system in MapleSim. Friction is a complex phenomenon and understanding its mathematical representation is crucial for accurate modeling. Here are some suggestions on how you can determine the input parameters for your model:

1. Breakaway friction force: This is the minimum force required to overcome static friction and set the object in motion. It can be determined experimentally by gradually increasing the applied force until the object starts to move. You can also estimate this value by analyzing the materials and surfaces in contact and their coefficients of friction.

2. Viscous friction coefficient: This represents the resistance to motion caused by the fluid medium surrounding the object. It can be determined experimentally by measuring the force required to move the object at different velocities. You can also estimate this value by considering the viscosity of the fluid and the surface area in contact.

3. Transition approximation coefficient: This value represents the transition from static to dynamic friction. It can also be determined experimentally by measuring the force required to move the object at different velocities and observing the change in friction behavior. You can also estimate this value by analyzing the materials and surfaces in contact and their coefficients of friction.

In general, these input parameters can be determined experimentally by conducting tests on your system and analyzing the data. However, if you have limited access to experimental data, you can also estimate these values by considering the materials and surfaces in contact and their physical properties. It's important to note that the accuracy of your model will depend on the accuracy of these input parameters, so it's best to gather as much data as possible.

I hope this helps. Good luck with your model!