Imperfection Analysis
Imperfection Analysis
(OP)
Dear All,
I am currently designing a monolithic spherical vessel under uniform compressive pressure and would like to investigate how deviations from the "ideal" spherical shell shape (e.g. non-uniform thickness) will affect its critical buckling load.
Any suggestions on approach this problem would be greatly appreciated.
Kind regards
burningliquid
I am currently designing a monolithic spherical vessel under uniform compressive pressure and would like to investigate how deviations from the "ideal" spherical shell shape (e.g. non-uniform thickness) will affect its critical buckling load.
Any suggestions on approach this problem would be greatly appreciated.
Kind regards
burningliquid





RE: Imperfection Analysis
The analysis will cut back with successively smaller load increments very near the buckling load until it eventually halts for a number of reasons. Your critical buckling load is within a few percent of the %load that it got to.
gwolf
RE: Imperfection Analysis
Then, run an eigenvalue (linear) analysis to get the buckling loads and mode shapes. You can then examine the mode shapes, and use these in an imperfection analysis.
There is a really good example in the ABAQUS docs;
"1.2.6 Buckling of an imperfection-sensitive cylindrical shell".
Regards
Martin Stokes CEng MIMechE