Condition Number of Stiffness Matrix

[Matthias Klärner [e-mail] [Abaqus]]

I am dealing with laminated materials differing quite a lot in thickness and
stiffness of the layers. I have a full model with all layers in extra elements to determine non-linear shear, too.


Thus, I want to *extract the condition number of the global stiffness
matrix*.


I only found the element matrix output of the whole stiffness matrix, but
not the condition number!


Does anyone know a way?


And how about pre-conditioning?






Thanks a lot!

[[e-mail] [Abaqus]]

What about estimating the condition number from the ratio of the largest eigenvalue to the lowest eigenvalue?
You can calculate the eigenvalues by performing a frequency analysis in Abaqus (assigning mass properties at your model so that its global mass matrix becomes equal to the unity matrix). Another more flexible solution would be to process the stiffness matrix in a software outside abaqus to do what you need.


Regards,


_______________________________________________
George Papazafeiropoulos
First Lieutenant, Infrastructure Engineer, Hellenic Air Force
Civil Engineer, M.Sc., Ph.D. candidate, NTUA
Email: ***@yahoo.gr
Website: http://users.ntua.gr/gpapazaf/