3 ms·

FEA is used for design assistance usually, not considered good enough for verification in aerospace at least (not sure about other fields). i.e you can design t

by jpgvm 4y ago

FEA is used for design assistance usually, not considered good enough for verification in aerospace at least (not sure about other fields). i.e you can design the wing for a certain loading using FEA to model but then a proper test needs to be completed that tests the wing to breaking point to verify the design meets constraints.

mihaaly 4y ago
This must be true for any other analysis and calculation methodologies too.
- jpgvm 4y ago
  Well I wonder sometimes. Like you don't build a building and then stress test it... so there must be some fields where simply adding the 30-50% margin for error is good enough.
  - mihaaly 4y ago
    Absolutely. Safety factors allow engineers to have good night sleep. ; ) Luckily in constructions the use of novel methodologies aren't that common like in other industries so previous small and sometimes big scale tests - also previous spectacular failures - predict future behaviour to a good extent with predictable risk factors, considered in safety factors. Also known things combined the known ways are preferred (or expects huge costs for your one off object). National building regulations on methodology encode some of these experiments (considering load, material and manufacturing uncertainties on top, also the time factor in the many many decades range) laying a legal foundation on what can and what cannot be done and expected, where the responsibilities start and end. Basically no need to test all new designs if proper - and legally approved - methodologies and procedures are used, rules and methodologies cautiously formed represent the validation there. (unusual shapes, materials, compositions, methodologies not covered by regulations might require much more scrutiny then, and potentially much higher safety factors too. ;-) )
  - iancmceachern 4y ago
    Exactly, in many safety critical areas its required by law. It's way more than 30-50% though. In medical devices it's 4x-10x.

by jpgvm 4y ago

mihaaly 4y ago

This must be true for any other analysis and calculation methodologies too.

jpgvm 4y ago
Well I wonder sometimes. Like you don't build a building and then stress test it... so there must be some fields where simply adding the 30-50% margin for error is good enough.
- mihaaly 4y ago
  Absolutely. Safety factors allow engineers to have good night sleep. ; ) Luckily in constructions the use of novel methodologies aren't that common like in other industries so previous small and sometimes big scale tests - also previous spectacular failures - predict future behaviour to a good extent with predictable risk factors, considered in safety factors. Also known things combined the known ways are preferred (or expects huge costs for your one off object). National building regulations on methodology encode some of these experiments (considering load, material and manufacturing uncertainties on top, also the time factor in the many many decades range) laying a legal foundation on what can and what cannot be done and expected, where the responsibilities start and end. Basically no need to test all new designs if proper - and legally approved - methodologies and procedures are used, rules and methodologies cautiously formed represent the validation there. (unusual shapes, materials, compositions, methodologies not covered by regulations might require much more scrutiny then, and potentially much higher safety factors too. ;-) )
- iancmceachern 4y ago
  Exactly, in many safety critical areas its required by law. It's way more than 30-50% though. In medical devices it's 4x-10x.