tire model/spring dumper

francesca_21990

Hi everyone, i'm a very novice at MotionView so I apologize in advance if my questions may seem trivial.

 

I have imported in MW a cad file (attached), my problem is: my cad file includes tires, but obviously these tires are not realistic (they are rigid bodies). I've put a jack plate to make wheels move up and down (to simulate for example a wheel that takes a hole) with the aim of estimate the force that will affect the frame. For this reason, tires cant be rigid bodies.. Is correct to use a spring dumper in order to have a better and more realistic representation of the wheel? Where to put it? Between a point, for ex the center of the wheel, and the jack plate or in place of the wheel? Ho to estimate k ad c coefficients? Or is there any other method? I think that the force on the frame, if the wheel takes a bump, won't be realistic if the wheel is simply a rigid body from a cad file: that's my problem!

 

Thanks in advance.

Unable to find an attachment - read this blog

Chris Coker_21312

If you are trying to simulate the loading effects of a tire going through a pot-hole, a simple spring-damper approximation will not give you the correct loading into the suspension.  You should be utilizing a proper tire model, or using physical test data collecting using wheel forces transducers, and applying those to the spindles.

 

We have an extensive library of vehicle models built into MotionView.  These can be a guide on how to properly set up a model like this.

 

For your question about K&C coefficients for your trailer model....What values do you want to compare with?  The purpose of measuring K&C is to evaluate a design vs. some target data, or evalute two different vehicles, etc.  Our vehicle libraries are already setup to run K&C analysis.  You can likely adapt your model to work with those.  Note that starting from CAD data for building a vehicle model is not the most efficient approach.  Typically, we encourage users to start with an existing suspension template.  Then you can take advantage of the existing events (full vehicle, half-car, K&C, etc) that have already been created.  Your existing model will not work with the existing event library without significant modification.