Knee Speed/ Velocity Split for damper

AI Thread Summary
The discussion focuses on determining the ideal knee speed or velocity split for a car's damper to optimize comfort, specifically relating it to the crossover point in the displacement transmissibility graph. The crossover point is defined at the square root of two for the frequency ratio, but the challenge lies in correlating this with damper velocity. The relationship involves understanding that damper velocity is influenced by the amplitude of damper displacement and road disturbance amplitude, making it complex to establish a direct correlation. The conversation highlights the need for a deeper understanding of vibration theory to navigate these relationships effectively. Ultimately, achieving the desired damper performance requires careful consideration of both frequency and amplitude factors.
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Hey guys I'm trying to figure out the ideal knee speed or velocity split for a particular car that I'm designing. What I'm trying to do is relate the knee speed (or crossover speed) of my damper to the crossover point in the displacement transmissiblity graph so that I can achieve optimum comfort in most situations. Please refer to the .png files that I've attached. Any help would be very appreciated!
 

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By the way, what I mean by the crossover point of the transmissibility plot is at the square root of two for the frequency ratio.
 
This might help you understand what you are trying to accomplish: http://www.optimumg.com/docs/Springs&Dampers_Tech_Tip_4.pdf
 
That's exactly what I've just read actually. I've read the whole article but my only question out of that article is how to get that split mentioned. All the article said was "
if you’re feeling adventurous, correlate the crossover point on the transmissibility graph to a damper velocity as a split point to start from". My question is: how do you relate them??
 
I have basic knowledge on vibration theory as I've already taken a course on it but it didn't cover complex situations topics such as the one I'm asking. It only covered the theory aspect with the plots.
 
Honestly, I've been looking at this many ways and can't see how you could correlate the two. The damper velocity is related \omega A where A is the amplitude of the damper displacement. So the same damper velocity can be achieved by a small displacement at high frequency or a large displacement at a low frequency. The displacement is a function of the road disturbance amplitude Z as well as the transmissibility ratio (which is also a function of the frequency TR(\omega)). So you get something like v = \omega TR(\omega)Z. Even if you set \omega = \sqrt{2}\omega_n, there is still Z that will affect the damper velocity.
 
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