Roll Centre Analysis

[dancin stu]

Just wondering what method teams use for analysing roll centre migration under roll conditions, do you use geometrical or force based calculations?

Just trying to see how many people have gone down the force based route, trying to find more info on it, got an insight in how to do it by a vehicle dynamicist, but he wouldnt give me the whole answerhttp://fsae.com/groupee_common/emoticons/icon_wink.gif, and also theres the short bit in Chassis Design and Principles, but does not really elaborate

[dancin stu]

Just wondering what method teams use for analysing roll centre migration under roll conditions, do you use geometrical or force based calculations?

Just trying to see how many people have gone down the force based route, trying to find more info on it, got an insight in how to do it by a vehicle dynamicist, but he wouldnt give me the whole answerhttp://fsae.com/groupee_common/emoticons/icon_wink.gif, and also theres the short bit in Chassis Design and Principles, but does not really elaborate

[Ben Beacock]

We were using the demo version of Performance Trends Suspension Analyzer and just bought the full version. Computes roll centers and their movement under all conditions you can think to give it. Only catch is that its all in inches and all our design is in metric.

Ben Beacock
Co-Manager
2004 Gryphon Racing - University of Guelph (http://www.soe.uoguelph.ca/uogracing)

[Sam Zimmerman]

If I understand this correctly, many software programs use a kinematic based roll center analysis rather than a force based analysis. I just read Dixon's paper on the subject today and I am now convinced that kinematic based roll center analysis methods use assumptions that are unrealistic and therefore the analysis is not valid, which makes some software programs invalid.

Of course I may be convinced of something entirely different next week. http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

Sam Zimmerman
Vandals Racing (http://www.uidaho.edu/~racing)

[dancin stu]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Sam Zimmerman:
If I understand this correctly, many software programs use a kinematic based roll center analysis rather than a force based analysis. I just read Dixon's paper on the subject today and I am now convinced that kinematic based roll center analysis methods use assumptions that are unrealistic and therefore the analysis is not valid, which makes some software programs invalid.

Of course I may be convinced of something entirely different next week. http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

Sam Zimmerman
http://www.uidaho.edu/~racing<HR></BLOCKQUOTE>

yeah thats what i have been thinking, glad im not the only one, what paper is that of Dixons? can you provide the sae number?

just want to get an idea of the differences between them and how large thay are, this years car I've had to use a geometric based analysis, because its what ive spent the last god knows how many years of my life reading up about it, but the more you speak to people in the business you realise as you say that it is not really suitable

[Sam Zimmerman]

I am away from school right now but I will try to get you the number when I get back. Your last sentance is ironic because it was a contact "in the business" who told us about the Dixon paper. http://fsae.com/groupee_common/emoticons/icon_smile.gif

Sam Zimmerman
Vandals Racing (http://www.uidaho.edu/~racing)