Modal analysis

[hrodrigues]

hi
i'm performing some modal analysis in a 3D model.
i'm having the following message:
ProfileSPDLinDirectSolver::solve() - aii < 0 <i, aii):(1372, 0)

do you know what this is ?
thanks in advanced
Hugo

[Jhno]

Your matrix failed.
Either your model is ill defined (check your fix condition, for a start) of you may want to try to use a fullgeneral system.

[fmk]

as the previous post stated you need additional boundary conditions. however, using a full general solver will not help and not quite sure why that was in the previous post,

[Jhno]

Well, outside of being a fix problems, I thought maybe it's matrix was not sym. so that the profileband would fails.

[fmk]

Profile is not going to check if symm or not .. it is pretty hard to get an unsymmetric matrix in OpenSees with documented elements and materials.