Analysis for MIL-STD-810F, Section 516.5 Procedure VII - Rail Impact?

[winpop123]

This may be better put in the "Military" category not sure.

Heres the issue. If you have the requirement listed in the subject above, what data or direction is available to meet this criteria?

I also have the requirement of 516.5 Procedure V - Crash impact.

My thoughts are that Procedure V is a much worse case in terms of designing hardware to meet the requirement (ie) 75g's @ 6 millisecs for ground vehicle equipment. I know how to design to meet that expectation and plan on going forward to do so. Without any additional guidance from MIL-STD-810, I don't see how one can really design to meet the Procedure VII requirement.

Thoughts?

Thanks

 

[IRstuff]

I'm not sure I follow.

Both the crash and rail impact requirements are tests for structural integrity. The equipment simply needs to not break, break loose, or visibly deform.

The question is what does YOUR requirement actually says. Beyond that, it seems that both the descriptions of Proc. V and VII have sufficient failure criteria for you to design to.

TTFN

 

[winpop123]

Thanks for rapid response. Let be be more specific.

Absent of advanced FEA techniques, one can simply take the mass of the article in question and multiply it by 75 in the case of the crash load to get an idea of the acceleration teh hardware will be subjected to and then do appropriate calculations.

If I were to be working in the vibration section of MIL-810 I could take a PSD curve and make some assumptions and calculate max g loading and make appropriate calculations.

Now look at Procedure VII. I see no PSD curves. No loads, no times, etc.

There are speeds of the train but I have no idea of damping factors on rail cars etc. How do I know the actuall load put on teh hardware from the test described without running the test?

thanks

 

[IRstuff]

You should then contact test labs or do some websearching:

http://www.mechsim.com/TEAprojects.html

STINET:

http://stinet.dtic.mil/

may have some relevant documents:

http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=A176100&Location=U2&doc=GetTRDoc.pdf

TTFN