deriving material properties (E)

[Tmoose]

We use various metal and glass/epoxy composites.
We just paid a heap of dough for a lab to do some cryogenic testing (tensile, comperession, and bend) to provide modulus of elasticity data for our popular recipes. The results were botched badly and heartbrakingly inconsistent.

I've been thinking that some impact testing of a simple beams warm and cold would give us some insight to the modulus of elasticity. I've made some Google searches and have not found any references yet.

 

[gwolf]

Try matweb.com

 

[YoungTurk]

Strictly speaking, a typical impact test will not give you an E value. However, if you use a setup with two piezo films, you can fairly easily measure what is referred to as the sonic modulus of elasticity. If that's along the lines of what you're looking for you should be able to turn up some literature by searching for sonic modulus.

The basic idea is to capture the time of flight for a stress wave over a known distance with the piezofilms. The stress wave is initiated by striking one end of the beam. You'll need a simple high speed two channel DAQ for this (and the associated software) in addition to the piezofilms.

But be careful; inclusions, cracks, and voids can greatly affect the SMOE value. I'd consider this a "poor mans" version of ultra-sonic modulus measurement, where the time of flight of an ultra-sonic signal imposed on the specimen with specialized equipment is measured.

 

[Tmoose]

This is what I meant by impact test. Sorry.

http://www.skfcm.com/service/support2/New Library/CM3010 Bump Test Microlog.pdf