Adams/car rc vertical
Adams/car rc vertical
(OP)
Hi guys,
Currently I am working with Adams/car to improve the suspension of our formula student racing car. There is one particular problem I encounter, when plotting.
I have been using the fsae template to remodel our current suspension. That has worked almost without a problem.
The problem is that, after simulation, when i try to plot wheel travel over roll center location vertical, the roll center does not act as I anticipated.
Also by changing the location of the inner tie rod, the roll center will move.
I have attached the template. Maybe someone knows why that particular problem is happening.
Thanks in advance.
Currently I am working with Adams/car to improve the suspension of our formula student racing car. There is one particular problem I encounter, when plotting.
I have been using the fsae template to remodel our current suspension. That has worked almost without a problem.
The problem is that, after simulation, when i try to plot wheel travel over roll center location vertical, the roll center does not act as I anticipated.
Also by changing the location of the inner tie rod, the roll center will move.
I have attached the template. Maybe someone knows why that particular problem is happening.
Thanks in advance.
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RE: Adams/car rc vertical
What did you expect exactly?
perhaps a plot would be useful
"by changing the location of the inner tie rod, the roll center will move."
depends on your definition of roll center. I'm not surprised a force based roll centre would move with changes to ITR. I'll check whether geometric roll centre height moves with ITR location.
what sort of suspension is this?
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Adams/car rc vertical
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Adams/car rc vertical
I'm merely working with what I've got. The steering system is fix, aswell as the upright. All I can change are the control arms.
Maybe I am plotting the wrong? roll center. I only know how to plot "wheel travel" over "roll center center location vertical".
I have attached the plot though.
I have calculated the instant centers in excel, aswell as the roll center height and have used vsusp.com to verify. Both will give me
a rc height of around 25mm above ground, whereas adams will plot a rc height of -14 at equilibrium.
best regards
RE: Adams/car rc vertical
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Adams/car rc vertical
I've attached a plot of "toe angle over wheel travel" for parallel travel.
best regards
RE: Adams/car rc vertical
Negative rch is not bad in itself, but I think the bump steer plot shows that you have bigger problems.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Adams/car rc vertical
That's why all I can do is, change the position of the upright and the lengths of the control arms.
It doesn't bother me that the roll center is negative, but the fact that it's not compliant with what i've calculated nor is it coming even close to
what vsusp is calculating.
RE: Adams/car rc vertical
I prefer using force based roll centre heights as that actually measures something I'm interested in.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Adams/car rc vertical
thank you for your input, i will attach an excel sheet with my hardpoints.
I know that there is a difference between forced base and geometrical roll center, yet I don't know what the difference is.
Maybe you can link me an article about that, i'd be very thankful for that.
best regards