Pneumatic shock tester

[floattuber]

I'm looking for information on building a pneumatic shock tester to simulate pyroshock testing. What we have in mind is using air pressure to shoot a projectile into a beam fixed on both ends to replicate a shock spectrum. We have a paper from Sandia labs in which they built several shock testers similar to this. Does anybody know where I can find more information on the subject?

 

[GregLocock]

Mythbusters?

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[monkeydog]

What is the report from Sandia Labs?
Were they able to replicate the pyroshock spectrum?

 

[btrueblood]

A wise old stress guy once said that a mechanical (i.e. shaker table) simulation of a pyro shock would tend to over-test the DUT at low frequencies, and under test at higher frequencies.

Our DUT was a very fragile tungsten filament. Broke several development prototypes on a shaker table before improving the mounting enough that we felt good about proceeding to the qualification test.

He was right. The pyro test data showed lots of high-frequency content, and very little low-freq (where the filament was most susceptible to damage). We passed with flying colors.

 

[floattuber]

Yes, Sandia was able to replicate some pyroshock spectrums and it was outlined in a paper titled "Simulation of pyroshock environments using a tunable resonant fixture".

http://adsabs.harvard.edu/abs/1992STIN...9322975D

They came up with 2 different kinds of tables, one like the one I described above and another that pneumatically drove a sled into a target which held the UUT.

 

[btrueblood]

Well, have you tried contacting the authors of that paper, or the NASA STI or Technology Transfer office?

 

[floattuber]

Yes, my boss contacted one of the authors of the paper and she told him to buy the paper. The paper is actually quite helpful, but I wanted to know if anybody else has done this. It would be nice to get more than one data point.

 

[btrueblood]

Wow. That's it? Normally, NASA is very proactive in technology dissemination (it's part of their charter), and positively begins to drool if you mention the idea of liscensing their invention...is their idea patented at all? If so, who owns the patent rights, and can you talk directly to them. If not patented, and the author(s) have moved on to other fields/tasks, then you are stuck: the idea is an "orphan". You will have to recreate the ideas from semi-scratch, with only the original paper to go by.

 

[monkeydog]

I was able to get a copy of Phase 2;
In the last paragarph of the report it states:
"All of the inital goals of this project have been attained with the Phase I and Phase II apparatus. The Phase I apparatus was patented (ref 9) in 1996. .... This is an area where we see the potential for increased involvemnet by Sania's Shock Lab and other test facilites. ...

 

[btrueblood]

Ok, find the patent owner, and ask them who is currently liscensing it, talk to that lab, ...