spring and damping sympatico

[meb]

How are actual damping rates determined? I understand that spring rates define some of the damping decisions/characteristics, and, that a mutual harmony must exist between the front and rear damping, but what are some of the actual relationships and units used to define damping...for a given spring rate?

[ubrben]

Originally Posted by meb

How are actual damping rates determined? I understand that spring rates define some of the damping decisions/characteristics, and, that a mutual harmony must exist between the front and rear damping, but what are some of the actual relationships and units used to define damping...for a given spring rate?

sprung mass natural frequency will be 1/2*pi * sqrt(k/m) where k is spring rate and m is the sprung mass supported at that corner.

Critical damping coefficient is given by 2*(sqrt(k*m))

Everything I've read suggests around 0.7 as a ratio of critical damping. So you just do 0.7*2*(sqrt(k*m)) to give you you're damping coefficient.

Best advice in this area is on OptimumG's website:

http://www.optimumg.com/news_archives.htm

Ben

[meb]

I forgot I began this thread. Thank you ubrben.

I have a feel for what rates work for me and my rig and so far have been reasonably successful. But I'm always trying to improve.

Milliken too often, in my opinion, begin discussion about such things in what appear to be the middle of the conversation...I always find myself looking for the beginning...

Great Link!!! Thanks again.

[flavorPacket]

rcvd assumes an engineering background, which would include a basic level of dynamics/vibrations knowledge.

[ubrben]

Originally Posted by flavorPacket

rcvd assumes an engineering background, which would include a basic level of dynamics/vibrations knowledge.

RCVD is not high level engineering. Certainly the second half where all the roll stiffness and damping stuff is pretty basic.

The sort of questions you're asking are getting beyond what's in RCVD, so if you're struggling with that I'd question what the point of exploring more complex areas is.

Part II of RCVD is high school maths. Only Part I includes some calculus.

I bought RCVD when I was 16 before I even left high school.

Ben

[flavorPacket]

anyone can plug and chug, I agree. But my point is that to understand where the equations in milliken come from requires basic dynamics knowledge (perhaps intermediate for the stability and control section)

[meb]

My background is in Landscape Architecture and as such grading and drainage/perc calculations are quite important - vital. The math is very basic, but understanding what the values mean in real life - experience - are far from basic. This is where I am. I can do the math, but I do not have enough real-world experience to understand what the values mean. So I am missing a real world frame of reference - not really found in Milliken.

I appreciate the link, however. It contains more usefull info.