RV8 cockpit bulkhead hole cover...I have a failure but really a success. fatigue testing the panel hole cover retainer to 1627 cycles to the max stop. it had good force until the snap as it caught me unaware. since Low Cycle Fatigue (LCF) is primarily a function of the max stress (lower stress cycles don't count for much, Miner's Rule, do the math) and the retainer does not bend to the max stop during normal installation and removal, it can probably survive twice as many cycles for normal use, but this is not a statistical test, just one. how many cycles will this part have during it's normal lifetime, probably not over 100.
50 cycles tested at a time. my thumb is sore.
if this was a new turbine disk, you would determine the probability of a defect in all the disk critical regions and then determine the life of those regions and then combine them to have a life for the disk. then divide that number by 3 and that would be the starting life for that part. after some experience, work a life extension program with refined analysis and experience to extend the life. for turbine design it is statistical. do you understand how much energy is released when a turbine disk burst? you don't want to know, and no structure can contain except a really thick concrete wall. when they burst, such as in a dedicated burst test, it is usually 3 pieces. think about that the next time so sit by the engine on an airliner. mechanical engineering at the highest level. need to buy one new replacement high pressure turbine disk for a large engine? probably about 3M dollars but it may be higher by now.
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pump up the techno polka! probably good to dance to after a couple beers.
Tinlicker - Oudegracht (Official Tinlicker Channel)
https://youtu.be/Tle_t4kMxO4
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a message from the owner who received the free Delta Zulu control mount holders for letting me use his headset for a pattern...... nice to hear it is working fine. sail on!
I keep trying to remember to get a photo. I mounted mine in my 8 low on the bulkhead that attaches to the main spar. It’s gonna be hard to see, but I promise I’ll remember….. Works great by the way!!!
