How do you Insert a FEM buckling perturbation into a FEM cylinder?
How do you Insert a FEM buckling perturbation into a FEM cylinder?
(OP)
Hi Fellow engineers,
If you run a buckling analysis and you want to use the buckling mode. To introduce a small buckling perturbation. Where do you have to look at?
Eigenvalue and/or Eigenmodes? Is the (negative)frequency of any importance?
Thanks in advance.
If you run a buckling analysis and you want to use the buckling mode. To introduce a small buckling perturbation. Where do you have to look at?
Eigenvalue and/or Eigenmodes? Is the (negative)frequency of any importance?
Thanks in advance.





RE: How do you Insert a FEM buckling perturbation into a FEM cylinder?
If you use ANSYS, they have a model update function to let you introduce a small perturbation to the structure.
RE: How do you Insert a FEM buckling perturbation into a FEM cylinder?
You can examine the imperfection sensitivity using Kioter's method. A complilation of programs to examine multi-modal interactions is presented in WRC Bull 313. These show that the coupling of adjacent modes (m+n) and (m-n) can produce lower bounds than a single bifurcation mode.
There are several papers at http://www.volcano.net/~d.citerley that examine the responses of shells to various imperfection geometries. I suggest that BuckTV examine these papers to gain a better appreciation as to what is involved.
RE: How do you Insert a FEM buckling perturbation into a FEM cylinder?
i suggest u to work through linear petrubation step( under load option). Here u can introduce buckling petrubation.And give time steps according to test run (I hope u need to give more steps in ur case). And as analysis is done, if u want to check the buckling load..the eigen values give that. Or if u want to check the shapes of ur model, check the eigen vector.
good luck,
Krishi