nodeMass command error

[Ricsey]

Dear all!

I've updated the latest Opensees and I wanted to use my scripts to my thesis work. They based on the nodeMass command. From the previous versions, this command's output was the nodal mass + some memory garbage. The nodeMass command with the newer version of opensees now only returns only memory garbage and it is really frustrating. I can handle the problem with another solution (e.g. I put the masses into a list and reading them from there), but all of my script files to my thesis work are now nothing...
Is there any solution to this or this is a bug of the new version which would will fixed in the future?

[fmk]

i have replaced the new windows executables with newer ones in which this bug is fixed.

[Ricsey]

Thank you very much McKenna for the fast reply and fast uploading!

[vsaggelidakis]

Hello to everyone!

If I don't give the masses directly to the nodes, but instead use the <-mass $massDens> choice while modeling the Elements,
I can't aquire the node masses using the "nodeMass" command, although for solving the model, for a lumped-mass approach,
the program has to distribute the masses to the nodes.

Is there a way to get those masses even in the form of the Mass Matrix?
(The need to get those masses arises when I compute the Participation Factors for every Mode of the system)

Thanks in advance!

[fmk]

a round about way is possible using the printA command .. 2 analysis, first static and do printA that gives the K matrix, do transient analysis, Newmark, another printA after an analysis step willgive the combined a1K + a2M (don't include Rayliegh damping).

alternativily CentralDifference method would just have M matrix * some factor 1/dT^1

[vsaggelidakis]

Prof. McKenna thank you for the fast reply!

Using your first suggestion, are the coefficients a1,a2 the ones computed for Rayleigh damping?
If they are and I don't use Rayleight Damping, I can't know their values, since I will not have
given the two circular frequencies from which they will be computed.

Kind regards,
VA

[fmk]

no .. they are the factor that Newmark would add to the mass and stifness matrix to compute the tangent matrix used in the Newton iterations.

[vsaggelidakis]

Thanks again,

Just to be sure I got this right, aren't the factors a0, a1 applied to the Mass and Damping Matrices, so that [K]={K}+a0*{M}+a1*{C}
and so I will only need a0 if I neglect damping?

Gratefully,
VA

[fmk]

yes