Dear all,
has consistent mass matrix been implemented in any element?
i've seen nonlinear elements have a $massDens entry which is used to form a lumped mass matrix
Consistent mass matrix
Moderators: silvia, selimgunay, Moderators
consistent mass matrix
We (almost) exclusively use consistent mass matrix in 8, 20, 27 node brick, (for both single phase and coupled analysis).
There used to be a bug/feature somewhere in there (I can dig it out) which would only use diagonal members of mass (assuming lumped mass I guess) even if you supply the consistent one... as for beams, not sure, try making a small test, linear beam, displacement based is a actually a closed form solution for beam theory (l'Hermite polinomials are not chape functions, they ARE the solution to diff. eq.) and then compare with closed form solution for say vibrations of a continous cantiliver...
Boris
There used to be a bug/feature somewhere in there (I can dig it out) which would only use diagonal members of mass (assuming lumped mass I guess) even if you supply the consistent one... as for beams, not sure, try making a small test, linear beam, displacement based is a actually a closed form solution for beam theory (l'Hermite polinomials are not chape functions, they ARE the solution to diff. eq.) and then compare with closed form solution for say vibrations of a continous cantiliver...
Boris
we do use consistent mass
We do use exclusively consistent mass in all our solids (bricks with 8, 20, 21, 27 nodes)...
Boris
Boris