MIL-S-901D specific force questions

[Solly93]

I am working on a project that is going to be 901D shock test qualified. I have put some rather simple designs through the test with no problems, but I am having difficulty with the currnet design.
It would be helpful if I could get my hands on some actual accelerometer outputs of the test (medium weight table) to verify peak and more importantly duration of the shock. This and/or as detailed as possible papers, reports, etc about the testing.
Does anyone have any ideas or possible resources??

Thanks.

 

[IRstuff]

Yes, you need to contact the Navy's 901 shock facility. I don't have the specific contact information, but they have accel data from the barge testing is performed there. Their website is:

http://www.dt.navy.mil/code60/code662/code662.htm

If this intended for a US Navy application, the Navy has been requiring barge testing for ALL weight classes of equipment.

There is an NRL report 7396, "Shipboard Shock and Navy Devices for its Simulation" authored by E.W. Clements published July 14, 1972, which should be available from NTIS.

901 shock design is quite non-trivial, as the g-levels are generally in the high double-digits to moderate triple-digits. If your company has access to someone who's done it before, you should get that person involved.

TTFN

 

[boo1]

An additional resource is the Shock and Vibration Information Analysis Center at:

http://WWW.saviac.org

 

[IRstuff]

Sorry, their main page is:

http://www.dt.navy.mil/code60/code66.htm

TTFN

 

[boo1]

At SAVIAC you can contact Joel Leifer 301.596.0100 to obtain actual simular test reports

 

[magicme]

this doesn't answer your specific question, but there is a report from the Naval Research Lab, NRL Memorandum Report 1396, "Interim Design Values for Shock Design Of Shipboard Equipment". the report has equations for shock design levels, based on equipment weight, mounting location, type of ship, etc.

unfortunately i don't know where you might find an available copy, as i am not familiar with Navy websites, etc....perhaps someone else here can help with that.

regards,

daveleo

 

[IRstuff]

I suspect that 1396 predates the Clement report. In recent communications, the Navy basically says that there are no specific design equations, since the waveforms in question are too complex to model with equations.

The last contact we had was:

NAWC, Carderock
UNDEX R&D
Code 661
9500 Macarthur Blvd
Bldg 19, Rm A250
West Bethesda, MD 20817

TTFN

 

[magicme]

hello again

NRL-1396 gave specific shock g-levels for designing shipboard equipment based on type of ship, type of mounting, weight of equipment, etc. the equations for the g-levels were very simple and referred to constants that are tabulated in the report.

the equations are used to perform a DDAM (Dynamic Design Analysis Method) per with NAVSEA 0908-LP-000-3010 "Shock Design Criteria for Surface Ships" (though it also covers submarines).

the DDAM process for large systems is painful and complicated, but for a small component, it is easy to use the g-levels given above.....but again, i don't know if the document is still available.

daveleo

 

[boo1]

As i stated before:
At SAVIAC you can contact Joel Leifer 301.596.0100 to obtain actual simular test reports