I want to make an experiment to test how shock absorbing different materials are.
There are two solid discs (with 50mm width, 35mm depth). Between them there is a thinner disc, made of a soft flexible material. I have multiple materials available for the soft disc and want to know which one is best suited for absorbing shocks.
The idea was to place an FSR sensor under the soft material and measure the pressure when a force is applied to the upper solid disc.
I am very new to working with arduinos and all kinds of sensors and I am not sure if that is the best approach. Apparently it is not easy to get a precise measurement with an FSR sensor and I would at least need to calibrate the sensor. I hope to get a more reliable result, like Force in Newtons or Pressure in Pascal, and would like to know if that is possible with an FSR sensor. If not, are there other sensors that are suitable for this experiment and how would I utilize them to get an exact measurement?
Welcome to the Arduino forum. An excellent test using an Arduino.
But, you seem confused about shock absorbing material. If slows the timing of the force applied. It does not limit the force, as you have the experiment set up.
To actually measure the force change, you need to have a force sensor on both sides of the material. Top as well as bottom. Then measure the forces and the time difference between the force peaks.
I do not know if the common FSR will work fast enough for you experiment.
you can absorb and damp shock impulses. It's usually done this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated
Absolutely can be done that way. Or can be done with calibrated sensitive force sensors. The loss of force by the lower sensor is equivalent to the heat generated. But never done with hobby sensors. Not sensitive enough to force changes and reading to reading consistency.
It may not even be possible, depending on what you mean by "precise". FSRs are highly nonlinear, not necessarily repeatable over measurement cycles and not intended for force measurements. They are fine for detecting "more force" and "less force".
Please explain what you mean by "test how shock absorbing different materials are".
How would accurate measurements of force help with that?
In my job, a while back, we were testing air bag deployment switches. We used different materials of different shapes to taylor the decelleration envelope shape. We used accelerometers. The more shock absorbant materials spread the deceleration out versus time. This does require a sesor with high enough frequency response, but that would be the case with force sensor as well.
Note that for comparison ("Qualitative") purposes, you don't need "precision", calibration, or even conversion to common units. You can just compare raw data (hopefully averaged over a bunch of samples.)
Force in Newtons or Pressure in Pascal
I think shock is usually measured as derivatives thereof. G's (acceleration), Jerk, Snap, Crackle, and Pop
Check out datasheets for materials marketed as shock-absorbing; they should be some help.
Beware, since some of the best shock-absorbing materials can only do it once.
(Consider car bumpers or bike helmets.)
