How to introduce the initial imperfections?????

[prashant.sangule]

Dear sir,

I want to know about how to introduce the initial imperfections in crashworthiness analysis (QUasi-static analysis) for isotropic material using ABAQUS/Explicit.

I am doing the eigenmode buckling analysis for initial imperfections. But i do not understand how to use this buckling modes in quasi-static analysis as initial imperfections? I am also confused about the boundary conditions used in buckling analysis. Should the BC's be same as that is used in quasi-static analysis? I came to know to use *IMPERFECTION code in input file for initial imperfections.But how to do that?

Plz guide me abt this. I will be very grateful to you.

waiting for ur reply.

[Jorgen]

I am afraid that I do not understand your questions. Did you already perform a buckling analysis and are now trying to to a static analysis? Or vice versa? Or something else?

- Jorgen

[prashant.sangule]

ya...i have performed the buckling analysis...now i want to do dynamic/Explicit analysis....but i would like to know, how to introduce the buckling modes obtained from buckling analysis in dynamic analysis?

I hope u would get my question.

[Jorgen]

Oh, I think I see.

I don't think it is trivial to force a given higher order buckling mode. The lowest mode will happen by itself, but the higher order modes probably need to be forced in order to get started.

- Jorgen