Position sensitive damping/ non linear spring rates

[Brian Coat]

"... racing tends to lag production world ... " with a notable exception being the "inerter shock", which was adopted from academia by the racing industry. However, it is not really a spring or a damper so, I'll get back in my box!

[autodoctor911]

Well, since KISS doesn't seem to apply in F1, how about an external bypass around the piston at ride height with an inertia valve intended to open in lower speed turns, allowing stiffer low speed damping in the piston, and additional bypasses at points that would give a different damping rate when in droop, or significant compression, and maybe throw in a pressure storage chamber attached with more inertia valves to provide an effective change in spring force.

As to the math, I am working on understanding the reason for the spring and damper rate changes to change differently when the motion ratio changes. If the equations for each separately are the same with regard to the relation between wheel force and the force at the damper /spring unit, then when the motion ratio changes to increase the travel at the damper unit, the velocity of the damper shaft is increased at the same rate as the mechanical advantage of the spring, is it not?

Perhaps it is because the damping force with respect to shaft velocity is not linear?

[DaveW]

... with a notable exception being the "inerter shock", which was adopted from academia by the racing industry

Perhaps it shouldn't have been, with research. Figures 1 & 2 of Hogan's patent 2856179, dated 1954 illustrates an inerter design (with damping).

Perhaps it is because the damping force with respect to shaft velocity is not linear?

No it isn't. There is nothing non-linear in my analysis, just the assumption that performance depends mainly on damping ratio, which is fixed.

[Brian Coat]

Perhaps it shouldn't have been, with research. Figures 1 & 2 of Hogan's patent 2856179, dated 1954 illustrates an inerter design (with damping).

That is very interesting Dave. thank you.