Container Design
Container Design
(OP)
In analyzing DNV 2.7-1 containers, the primary load case assumed is a 2.5:1 load factor of the max gross rating of the container. Also, according to DNV 2.7-1 the allowable Von Mises stress is 85% of the yield stress (for steel).
I typically apply the ASD design method which, after code checks per H-1 & H-2, typically leads to my stresses maxing out at around 65% of the yield (roughly).
My question is this:
1.) Am I being overlly concervative by using the ASD method?
2.) Would the LRFD method by more realistic? Also is the 2.5:1 load factor a sufficient load case to apply this criteria as no load cases in ASCE really apply to a container.
Thanks in advance.
I typically apply the ASD design method which, after code checks per H-1 & H-2, typically leads to my stresses maxing out at around 65% of the yield (roughly).
My question is this:
1.) Am I being overlly concervative by using the ASD method?
2.) Would the LRFD method by more realistic? Also is the 2.5:1 load factor a sufficient load case to apply this criteria as no load cases in ASCE really apply to a container.
Thanks in advance.






RE: Container Design
I too have recently been involved in some Offshore Containers (never mind my user name).
To me a Von Mises stress of 85% is purely for guys analysing the frame in a 3D frame analysis software - that is a typical unit/readout.
I have a copy of some old school hand calculations that show a calculted bending stress of say 250 MPa as OK as it is less than 0.85 x 350 MPa (Grade 350 Steel).
I argue that that is incorrect as it is greater than 0.66 x Fy = 231 Mpa. (Australian Standard AS3990).
Am I correct?
Would be keen to get some opinions on this...
Regards.
RE: Container Design
Since containers fall outside the scope of ASCE, you are correct using DNV 2.7-1 for the load factor.