Impact force measured using an accelerometer mounted on the bullet - urgent please

[StathPol]

is your suggestion is to tap the bullet at the front face (point where the bullet hits the concrete)? if this is the case, the bullet needs to be suspended. Otherwise, how to impact the front face?

[StathPol]

I have tapped the rod at the top end. Then I tapped the bullet near the impact point.

The results changed as follow.

[StathPol]

Guys, 

How can I set up this bullet to find the natural frequency of this steel piece with the accelerometer mounted on the top surface? The point of contact is the bottom hemispeherical head. In which point of the bullet shall I hit with the impact hammer? If I leave it as it is on a steel plate, it will fall down. 

Thanks.

[thoult]

Somewhat late to the party, and I'm sure this doesn't help, but...

In a former life, working in ballistic testing, I started using polyvinylidene fluoride (PVDF) film to manufacture ballistic force gauges. They're disposable - you're usually firing a projectile through them - but they're relatively inexpensive and very thin.

If I remember correctly, it involved a circular sensel of PVDF film, maybe 50 um thick, sandwiched between copper conductors separated by an insulating layer like Tyvek or similar. The charge generated between the two surfaces is proportional to the stress applied, as with any piezoelectric crystal. You know the contact area - the area of the sensel - and hey presto, you can estimate the force applied at that point.

The dynamic response was phenomenal, although making them by hand was fiddly. So long as you mount them accurately so that you hit them, they were excellent for measuring impact forces during ballistic events on rigid materials.