rb1957
Aerospace
- Apr 15, 2005
- 15,672
We're (well a supplier is) using Tsai-Hill to analyze their structure. So FEA gives them a FI (= applied stress/allowable).
To calculate MS I've used RF = allow/applied = 1/FI, MS = RF-1 = 1/FI-1
Supplier is saying it is MS = 1/sqrt(FI) -1 because of the nonlinearities of Tsai-Hill. If this is the case, then it's something like a bolt analysis (where tension and shear interact with different powers). Then Rt = applied/allowable is "like" an FI ... but I understood that FI was for all stress components ?
I understand that Tsai-Hill is probably not the favoured analysis for composites these days. Is it 'Rong (how I emphasise Wrong), or just not current ?
Is there a better analysis ? the structure is not primary structure, a radome
"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.
To calculate MS I've used RF = allow/applied = 1/FI, MS = RF-1 = 1/FI-1
Supplier is saying it is MS = 1/sqrt(FI) -1 because of the nonlinearities of Tsai-Hill. If this is the case, then it's something like a bolt analysis (where tension and shear interact with different powers). Then Rt = applied/allowable is "like" an FI ... but I understood that FI was for all stress components ?
I understand that Tsai-Hill is probably not the favoured analysis for composites these days. Is it 'Rong (how I emphasise Wrong), or just not current ?
Is there a better analysis ? the structure is not primary structure, a radome
"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.