3.1.2 Concentrated Mass

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3.1.2 Concentrated Mass

Concentrated mass can be modeled with point mass/damping elements [Vol. Element Library]. Generally speaking, these elements don't influence the static behavior of the model, i.e., they don't have stiffness, strain or stress. In static analysis, the concentrated mass acts as concentrated loading for dead weight.

(syntax)

$\begin{figure}\centering \begin{tabbing} \texttt{'MATERI'} \\ [-1.0ex] \rule{14... ...xtit{my}}$_{r}\,$ \texttt{\textit{mz}}$_{r}\,${]} \end{tabbing} \end{figure}$

MASS: specifies the masses acting along the global XYZ axes respectively (orthotropic): M_X = mx , M_Y = my , M_Z = mz . (M $\geq$ 0 )If you only specify mx, then the mass acts equally along all three axes (isotropic): M_X = M_Y = M_Z = mx .

(file.dat)

'ELEMEN'
CONNEC
 48  PT3T  112
 49  PT3RO 132
MATERI
 / 48 /  1
 / 49 /  2
'MATERI'
   1  MASS    3.5
   2  MASS    5.5 3.6 7.8

This example adds two concentrated masses to the model. Element 48 of type PT3T simulates a translational inertia with a mass of 3.5 acting in the three global directions. Element 49 of type PT3RO specifies three different mass moments of rotational inertia, respectively acting around the X , Y and Z axis.

Next: 3.2 Damping Up: 3.1 Mass Previous: 3.1.1 Mass Density Contents Index

DIANA-9.3 User's Manual - Material Library
First ed.

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