/ADMAS

Block Format Keyword Assign additional non-structural mass to nodes or a group of nodes. Optionally the total additional non-structural mass of a part or a group of parts can be defined (applied to shells and solids only) or a surface mass can be assigned to a surface and Radioss would then compute the added node based mass value using area (volume) - weighted distribution.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/ADMAS/type/admas_ID/unit_ID
admas_title
If type = 0 or 1
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Mass grnd_ID
If type = 2
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Mass/Area surf_ID
If type = 3 or 4
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Mass grpart_ID IFLAG
If type = 5
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Mass1 node_ID1
Mass2 node_ID2
etc etc
MassN node_IDN
If type = 6 or 7, an additional list is provided
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Mass1 part_ID1 IFLAG
Mass2 part_ID2 IFLAG
etc etc IFLAG
MassN part_IDN IFLAG

Definition

Field Contents SI Unit Example
type Input type.
= 0
Mass is added to each node of node group.
= 1
Mass/N is added to each node of node group.
N being the total number of nodes in the node group.
= 2
Mass/Area - additional surface mass applied on the shell area.
= 3
Additional mass distributed on the part-group.
= 4
Final mass distributed on the part-group. 2
= 5
Mass is added to each single node.
= 6
Additional mass distributed on each single part.
= 7
Final mass distributed on each single part. 2
admas_ID Added mass block identifier.

(Integer, maximum 10 digits)
unit_ID Unit identifier.

(Integer, maximum 10 digits)
admas_title Added mass block title.

(Character, maximum 100 characters)
Mass Added mass.

(Real)

 [ kg ]
Mass/Area Added mass per unit area.

(Real)

 [ kg m 2 ]
grnd_ID Node group to which the mass is added

(Integer)
surf_ID Surface to which the mass per unit area is added.

(Integer)
grpart_ID Part group to which the mass is added.

(Integer)
node_IDN Node to which the mass is added.

(Integer)
part_IDN Part to which the mass is added.

(Integer)
IFLAG Flag to switch between area weighted distribution and volume weighted distribution of the added mass to parts).
= 0 (Default)
Volume weighted distribution (shell and solid parts).
= 1
Area weighted distribution (shell parts only).

(Integer)

Comments

  1. This option cannot be used in a 2D axisymmetrical analysis.
  2. Final mass replaces structural mass and final mass for each node must be greater than structural mass. In other words, non-structural mass for each node must be greater than zero. The element time step is not affected by the addition of non-structural mass since the nodal time step changes.
  3. Using /ADMAS additional mass and final mass is in the part level and the node level, not in the element level.
  4. Area or volume weighted distribution of the mass does not account for density of components (referred to the part-group). Therefore, for reasonable distribution of the mass, it is advisable to have the same material and property definition in components of the part group.