WTMASS and Eigenvalue in FEMAP/NASTRAN
WTMASS and Eigenvalue in FEMAP/NASTRAN
(OP)
Hi
I want to get the eigenvalues of an Objekt with FEMAP/NASTRAN. In FEMAP I can choose to change the WTMASS. Is it necessary? What is it exactly for?
I have tested it with an easy spring-mass-system and I only get to a right answer, if i haven't picked it.
Thanks for your help
I want to get the eigenvalues of an Objekt with FEMAP/NASTRAN. In FEMAP I can choose to change the WTMASS. Is it necessary? What is it exactly for?
I have tested it with an easy spring-mass-system and I only get to a right answer, if i haven't picked it.
Thanks for your help





RE: WTMASS and Eigenvalue in FEMAP/NASTRAN
WTMASS adjusts every term in the mass matrix by this factor, thereby correcting the inconsistency. If an analyst uses a consistent set of units (Mg in the above example), WTMASS is unnecessary (by default, it is 1.0--no adjustment made).
Brad