I have begun some testing on a single shim to determine if the shim deflects in planer or compound bending. I have recently had discussions with a knowledgable engineer with experience in this area and we share the idea that shims are inherintely stiffer and more resistant to compound bending. I have been able to take measurements of the shim while under deflection, but it has not been consistent. Has anyone performed testing or analysis that I can rely on and move to more advanced testing?

TH

oooh I like this

I have allways wanted to conect a strain gauge to the very outer edge of the shim and pull it .010" and see what it was in .001 increments . But I never camup with a reliable way to do it (in my brain at least) Kevin Stillwell is the only guy I know of who has played with this in depth ... there might be others ......

What have you tried ???

Not sure a point loaded strain gage would replicate the distributed load of a fluid. The method I have used is a closed loop hydraulic system. I vary the flow and pressure and determine the deflection with a probe and dial indicator. I initially tried this visually by making incremented marks in the acrylic tube where the valve sits. This is a project in work, trying to get my measurements more consistent.

TH

sounds interesting but there are threads my english isn't enough. you may know that shims don't provide a linear curve (the more shims the more linear it is),of course thicker shims need much more force to bend and if you want take a look at my hydraulic dyno of different shims:
www dot supercross-online dot de/Z/shims-thickness.jpg

I think there's a site you should know if you don't yet:
www dot peterverdonedesigns dot com/damping.htm

as I said maybe your question has an other direction, then sorry for writing stuff you don't need....

kawamaha,

Thanks for the post. I am aware of the that website, also that shim stacks are non-linear. I see from your measuring device sketch that you are experimenting using the same method I am. Interested in how you obtain 300+ ips and 290 psi. Also are you able to physically measure shim deflection accurately, or are you measuring flow and pressure only? Thank you again for your post.

TH

well, I guess I could meassure the shim deflection but never thought about it. if I ever want to do that I am sure it will be much effort.
I usually meassure the pressure, the flow is given by the control unit. to be sure the flow is the same at different stacks I switch between the two stacks with a valve (I know the flow isn't exactly the same after restart the pump circuit)

it's shown here:
www supercross-online de/Z/dyno.htm

due to a provider change page is still under construction

if you think 300psi is much I have to tell you I could go up to 3500psi