Ceboe
07-02-2014, 09:39 AM
For our SES we have to prove the equivalency to a minimum of 4 8mm grade 8.8 bolts.
What's the best way to prove this equivalency?
A grade 8.8 bolt will fail at 800 Mpa and it has a surface of 6.5 mm core diameter. This means that one M8 bolt will fail at 33.2 mm˛ * 800N/mm˛ = 26 560N
For four bolts this means 106 240N.
The suurface of our front bulkhead (with the hole cutout) is 115 000 mm˛
This means there will be a stress of 106 240/115 000 = 0.92 MPa on our front bulkhead. Which is substantially lower then the max E value for our lay-up, calculated in the SES.
Is this calculation sufficient to prove equivalency?
What's the best way to prove this equivalency?
A grade 8.8 bolt will fail at 800 Mpa and it has a surface of 6.5 mm core diameter. This means that one M8 bolt will fail at 33.2 mm˛ * 800N/mm˛ = 26 560N
For four bolts this means 106 240N.
The suurface of our front bulkhead (with the hole cutout) is 115 000 mm˛
This means there will be a stress of 106 240/115 000 = 0.92 MPa on our front bulkhead. Which is substantially lower then the max E value for our lay-up, calculated in the SES.
Is this calculation sufficient to prove equivalency?