max lateral frictions coefficient relative to camber

[andsund]

Hello, our team plotted maximal lateral friction coff to camber on different normal loads to find out what optimal camber for a turn with TTC. we got max my at 3.3 -3.5 deg of camber on different normal loads. Is this really reasonable?

Best regards Anders Sundström

[rmk36]

Originally posted by andsund:
...we got max my at...

Best regards Anders Sundström

My or Fy? Typo perhaps?

Anyhow, this question should be asked at the TTC forum and not the FSAE forum.

http://sae.wsu.edu/ttc/

[Claude Rouelle]

Hello Anders,

First question: For which tire? On which rim? At which pressure? (and I am not asking what speed, what wear (difficult to quantify) and what temperature)

I will answer this question if you show HOW you came with this number and what method you use to find these numbers

Do not forget that lateral force Vs slip angle Vs vertical load Vs camber is one thing and that longitudinal force Vs slip ratio Vs vertical load Vs camber is another.

Ideally you need both separately and combined (combined braking and cornering or combined acceleration and cornering for example)

But one think at a time: let's start with lateral grip (or normalized force, which what you call coefficient of friction) and camber: How did you come with 3.3 to 3.5 degrees ideal camber ?

Also who are you? What university / FSAE team do you work with? Unless you have a signature which tells us that it is always nice to introduce your self when you join a forum.

[Sormaz]

Originally posted by andsund:
Hello, our team plotted maximal lateral friction coff to camber on different normal loads to find out what optimal camber for a turn with TTC. we got max my at 3.3 -3.5 deg of camber on different normal loads. Is this really reasonable?

Best regards Anders Sundström

and what if it is reasonable? does that make it correct?
Be confident in your approach and you can be confident in your solution

[andsund]

Oh, my apologies for the bad manors, I'm new to writing on the forum and haven't got a signature yet. My name is Anders Sundström, Im from Sweden a University called Linköping University. Im with the formula student team called ELiTH Racing.

To the question, we use Hoosier 20.0 x 7.5 -13 rim 8''. Were using a the parameters and 1996 Pacejka Tire Model from TTC. I know these aren't perfect but its what we have thats working. And were looking at combined. So by some matlab code and the formulas from TTC we end up with a graf with maximum at -3.3 camber. We calculate max lateral force for different slip and calculate then max my, plot to camber.

I understand that we should be confident in what we do, but I was just looking for some feedback. Im sorry for the thread, I thought it was relevant to this forum.

Best regards Anders Sundström
Linköping university - ELiTH Racing

[Claude Rouelle]

1. My of Fy? I guess you mean FY, correct?

2. "Some" Matlab codes?

3. Can you show at least one graph of FY Vs Alpha for different Fz and different Camber?

[Zac]

Look for the visualization code BillCobb posted a while back. It'll provide a good start for what you're looking for.

[Goost]

Hey andsund,
I think it's relevant; I think the confusion is whether you mean self-aligning torque (Mz?) or lateral friction coefficient (MUy?). If you meant friction coefficient: from that set of data (raw) it seems the peak is highest with no camber. rmk36 is right though, the TTC forum may be better if you want to look at numbers more specifically. Personally, I wouldn't share code, and of course we can't post pictures:

Individuals and teams are prohibited from donating or selling the data to any other
individual, group, team or university, or posting it on the internet. […] The data may not
be used in any commercial application.

[Goost]

Looked at this after some data treatment: I can get similar values but they depend greatly on the vertical load used.

[andsund]

I plotted My to camber. it seems its not legal to show grafs from the ttc as GOOST said, thank claude anyway for the help! I just wanted a second opinion.

yes it depends on different loads.