SURFACE_LOADS
SURFACE_LOADS load_time_function_number = ltime, etc...
n, ( pres(j, n) , j = 1 , ncomp ) < for
n = 1 , nload >
< connectivity data >
(see Chapter 11)
Note Variable Name Type Default Description
Load_case_number integer [*] Load
case number (only required
in
Restart mode)
Generation_type list [list] Generation
type
list
Cartesian
Type list [*] Load
type
constant /
time_dependent
Load_time_function_number integer [0] Load time function
number
Number_of_loads integer [0] Number
of surface loads: Nload 
0
(only
required for no generation case).
Load_direction list [normal] Load
direction
normal /
x_1 / x_2 / x_3 normal
= normal to element face/edge
x_1
= in x_1 direction
x_2
= in x_2 direction
x_3
= in x_3 direction
(1) Phase_number integer [1] Phase
number
Element_shape list [*] Element
shape
four_node_quad
eight_node_quad
three_node_tri
six_node_tri
two_node_line
three_node_line
Geometry_type list [plane] Geometry
option
plane
axisymmetric
three_dimensional
Finite_deformation list [off] Finite
Deformation option
on / off If
on: use Updated (Deformed) Geometry
File_name string [none] File
name (optional). Name must
be
enclosed in quotation marks.
Note/
(1) Only applicable to porous media.
7.2.1 No Generation (List) Case
7.2.1a Surface Loads (Nload sets) – Two-Dimensional
Case: NEN = 2, 3
Note Variable Default Description
(1) N [0] Load set number 
1 and 
Nload
(2) PRES1(1, N) [0.0]
- - -
etc. - etc.
- - -
PRES1(Nen, N) [0.0]
(3) SHEAR(1, N) [0.0] Shear stress at node 1
- - -
etc. - etc.
- - -
SHEAR(Nen, N) [0.0] Shear stress at node Nen
Notes/
(1) Each surface load must be input on a surface load record. The
total number of surface loads must equal NLOAD read in on the control record.
The records need not be read in any particular order.
(2) The normal traction / pressure (force / area) is assumed to
be positive pointing inward, and is linearly interpolated between nodal
values. The positive outward normal
direction is obtained by rotating by - 90 degrees the direction (node 1 to node
2).
(3) The shear stress is assumed to be positive pointing in the
direction (node 1 to node 2), and is linearly interpolated between nodal
values.
7.2.1b Surface Loads (Nload sets) –
Three-Dimensional Case: NEN = 3, 4, 6, 8
Note Variable Default Description
(1) N [0] Load set number 1 and Nload
(2) PRES1(1, N) [0.0]
- - -
etc. - etc.
- - -
PRES1(Nen, N) [0.0]
Notes/
(1) Each surface load must be input on a surface load record. The total number of surface loads must equal
NLOAD read in on the control record. The
records need not be read in any particular order.
(2) The normal traction / pressure (force / area) is assumed to be
positive pointing inward, and is linearly interpolated between nodal
values. The positive outward normal
direction is obtained as the vector product of the directions (node 1 to node
2) X (node 1 to node 4).
7.2.2 Applied Surface Loads Generation Data
7.2.2.1 Applied Surface Loads Generation Data
Note Variable Default Description
(1) N [0] Node number 1 and NUMNP
(2) NUMGP [0] Number of generation points 0
=
0, no generation
≠
0, generate data
F(1,N) [0.0]
F(2,N) [0.0] Tangential traction at node N
- - -
Notes/
(1) Applied surface loads data must be included for each node
subjected to a nonzero applied surface loads.
Terminate with a blank record.
(2) If NUMGP is greater than zero, this record initiates an
isoparametric data generation sequence.
The scheme used is the same as the one for coordinate and initial
displacement/velocity generation (see Chapters 4 and 6, respectively). Records 2 to NUMGP of the sequence define the
applied surface loads of the additional generation points (see Section
7.2). The final records of the sequence
defines the nodal increment information and is identical to the one used for
coordinate generation (see Section 4.3).
After the generation sequence is completed, additional applied surface
loads data records, or generation sequences, may follow.
The generation may be performed along a line, over a
surface, or over a volume. For additional information concerning these options
see Note (2) of Section 6.1.
7.2.2.2 Generation Surface Loads Data
The applied surface loads of each generation point are
defined by a generation point surface loads record. The records must be read in order (J = 2,
3,...,NUMGP) following the applied surface loads record which initiated the
generation sequence (J = 1). A nodal
increments record (see Section 7.1.3) follows the last generation point record
(J = NUMGP) and completes the sequence.
Note Variable Default Description
M [0] Node number
MGEN [0] Generation parameter
= 0, applied surface loads
of the Jth generation points are input
on this record; M is ignored
= 1, applied surface loads
of the Jth generation point are set
equal to applied surface loads of node M which were previously defined; applied
surface loads on this record are ignored.
TEMP(1,J) [0.0]
TEMP(2,J) [0.0] Tangential traction at generation
point J
- - -
Note Variable Default Description
NINC(1) [0] Number of nodal increments for
direction 1
INC(1) [0] Node number increment for
direction 1
(1) NINC(2) [0] Number of nodal increments for
direction 2
INC(2) [0] Node number increment for
increment 2
(1) NINC(3) [0] Number of nodal increments for
direction 3
INC(3) [0] Node number increment for
direction 3
Notes/
(1) Each option is assigned an option code (IOPT) as follows:
IOPT Option
1 Generation along a line
2 Generation over a surface
3 Generation over a volume
IOPT is determined by the following logic:
IOPT = 3
IF(NINC(3)
= 0) IOPT = 2
IF(NINC(2)
= 0) IOPT = 1
7.2.3 Surface Nodal Connectivity Data
Consult
Chapter 11 for details. For 2D problems
NEN = 2 or 3, and for 3D problems NEN = 3, 4, 6 or 8.
Notes . .