Adjustable "Blade Type" Anti-Roll Bars Design Questions

[rabieng]

Hello everyone. Just wondering if anyone could help me out here. I am an automotive engineering degree student and as part of a design project I would like to model an adjustable twin blade sway arms in conjunction with an interchangable hollow, heat treated, high carbon steel sway bar (the standard gauge types used in US stock car racing) for a touring car, front suspension application. This may sound far-fetched to some but it was given to us as a "real design problem" for us to work on and have sleepless nights over ¦o) hehe

The pictures in the links below should give you an idea of what I am talking about showing an actual application of this design.
http://www.jaytorborg.com/anti-roll_bars.htm
http://www.hrpworld.com/index.cfm?f...&action=product

I have searched the forum but haven't as yet found the answers to my questions, specifically about this type of design. Now I have a few questions as I am not from the motorsport "scene". I understand how the design works, horizontal blade = "soft", on edge blade = "hard", the purpose of the ARB etc. I am however more interested in making calculations and a spreadseet for such a setup.

1. Does anyone know where I can find or do you have stiffness formulas relating to blade type ARBs? Any formulas for that matter which have direct application to blade type ARBs please?

2. Software, spreadsheets, books, photocopies, scans, websites, manufatcurers related to blade type ARB's... any recommendations or help here?

3. For the blades (arms) themselves, has anyone used aluminium, titanium or carbon instead of a steel alloy? What have your experiences been? (assume price is not an issue) What about surface finish of the blades? Which material would you say is safest for such an application and why?

4. Hollow Tube (Bar) of ARB: Powder coated or zinc coated finish? Why? Experiences please.

5. AR Bar - Chassis Mounting: I have seen a number of ARB mounting options integrating PU bushings, bronze bushings, roller and needle bearings. What really works? What would work best? Is the noise from the undampened STABILISOR unbearable during driving under race conditions? Your comments please?

6. Apart from driver/cockpit actuated systems, has anyone seen technician/mechanic adjustable blade type ARBs?... for pit-stop adjustment on the fly... i.e. FAST

7. Has anyone ever done Finite Element Analysis on such a part? Any tips for a novice?

Any help offered would be greatly appreciated. If you noticed, I even said please a couple of times hehe

Looking forward to sharing pic of finished design with forum at some point.

[TEAM78]

Originally Posted by rabieng

1. Does anyone know where I can find or do you have stiffness formulas relating to blade type ARBs? Any formulas for that matter which have direct application to blade type ARBs please?
.

Yes there are formulas (hand calcs best used in a spreadsheet)

Originally Posted by rabieng

2. Software, spreadsheets, books, photocopies, scans, websites, manufatcurers related to blade type ARB's... any recommendations or help here?
.

think where the principles are used for this type of thing not just on blade ARB's, for books on adjustable ARB's yes there are a couple but dont go into details. thats the ones I know of anyway.

Originally Posted by rabieng

3. For the blades (arms) themselves, has anyone used aluminium, titanium or carbon instead of a steel alloy? What have your experiences been? (assume price is not an issue) What about surface finish of the blades? Which material would you say is safest for such an application and why?
.

Surface finish is very important as it is closely related to fatigue, cracks are often initaiated at the surface, look at residiual stresses in your books, and maybe do a couple calcs on loads and fatigue life for your write up just to show your lecturers your aware of this

Originally Posted by rabieng

4. Hollow Tube (Bar) of ARB: Powder coated or zinc coated finish? Why? Experiences please.
.

as far as im aware, what ever takes your fancy really, zinc coatings are aimed at corrosion prevention

Originally Posted by rabieng

5. AR Bar - Chassis Mounting: I have seen a number of ARB mounting options integrating PU bushings, bronze bushings, roller and needle bearings. What really works? What would work best? Is the noise from the undampened STABILISOR unbearable during driving under race conditions? Your comments please?
.

Your aiming to reduce stiction here, bronze and roller bearings are popular. Noise and vibrations not an issue

Originally Posted by rabieng

6. Apart from driver/cockpit actuated systems, has anyone seen technician/mechanic adjustable blade type ARBs?... for pit-stop adjustment on the fly... i.e. FAST
.

Ive seen a couple, but to me they were extra weight really and additional complexity, if your doing this for FS it will do well in the design event but your team mates wont be pleased with the extra weight so its a compromise you have to decide on.

Originally Posted by rabieng

7. Has anyone ever done Finite Element Analysis on such a part? Any tips for a novice
.

more people than i care to count have done FEA on ARB's, what package do you aim to use, learn the limitations of the FE package your going to use and make sure you consider all the forces and not just the obvious ones.


which University are you at?

[Finchy]

Im guessing hes at herts as I am as well!



At least thats answered a few of my questions as well

[Rubinho]

Me too, what module's this for? BSc or BEng?

[Finchy]

Bsc - last year was a conrod design!

[Rubinho]

Remember Jeff gave us some suggestions for the material to use during the Motorsport Engineering lectures in Semester A. I can't remember what he said though but he did explicitly say that we should remember what he said for his module in Semester B. Sorry I can't be any more help though, I'm BEng