Having inhaled deeply of the arcana of burst disc sizing; I find that the
entirety of the available math is about sizing the plumbing, not about
design of the burst disc.
For my current actuated burst disc design I have a 1.5" diameter disk that
is clamped at 1.25" diameter. Operating conditions are air at (probably
something better than) -50 degree F (cold soak on the way to 200 Km) and at
an original 125 psia. Using the standard flat plate model I get this to be
0.050" thick disc of 6061-T6 providing a safety factor of 1.43.
If I am going to manufacture my own disk (an assumption worthy of review),
then is it correct to just assume a circular flat plate for initial design,
pending testing?
I will be testing prototype initiators next week; for now I am using an
e-match with a very small bit of nitrocellulose to generate the pressuring
gas. The nitrocellulose is in both "guncotton" and cord form. I expect
the former will be faster but the latter possibly easier to control since
cord length can be directly measured.
All testing will be at a local energetic materials facility...
Bill