RWALL
Bulk Data Entry Defines a rigid wall for geometric nonlinear analysis.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
RWALL | SID | RWTYPE | SLID | GISD1 | GSID2 | FRIC | DIST | ||
G0/ X0 |
Y0 | Z0 | IFILT | FFAC | |||||
X1 | Y1 | Z1 | X2 | Y2 | Z2 | DIA | |||
MASS | VX | VY | VZ |
Example
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
RWALL | 2 | PLANE | SLIDE | 23 | 5 | 3 | |||
21 | 2 | 1 | |||||||
11 | 24 | 12 | |||||||
340 | 7 | 13 | 32 |
Definitions
Field | Contents | SI Unit Example |
---|---|---|
SID | Load
set identification number. No default (Integer > 0) |
|
RWTYPE | Rigid wall type.
|
|
SLID | Sliding flag.
|
|
GSID1 | Grid
set ID defining secondary grids to be added to the rigid wall. (Integer > 0) |
|
GSID2 | Grid
set ID defining secondary grids to be deleted from the rigid wall. (Integer > 0) |
|
FRIC | Friction coefficient (ignored if
SLID=TIED or
SLIDE). Default = 0.0 (Real ≥ 0) |
|
DIST | Distance for secondary search. Initially the secondary nodes can be defined at a
distance lower than DIST. (Real > 0) |
|
G0 | Grid
identifier defining M, definition ignores
Y0 and Z0.
Moving rigid wall. (Integer > 0) |
|
X0, Y0, Z0 | Coordinates of a point M defining rigid wall
location if G0 not defined.
Rigid wall does not move. (Real) |
|
IFILT | Friction filtering flag. 3
(Integer) |
|
FFAC | Friction filtering factor. Default = 0.0 (Real) |
|
X1, Y1, Z1 | Coordinates of a point defining M1 for
RWTYPE=PLANE, CYL,
PARAL. (Real) |
|
X2, Y2, Z2 | Coordinates of a point defining M2 for
RWTYPE=PARAL. (Real) |
|
DIA | Diameter for
RWTYPE=CYL or
SPHER. (Real > 0) |
|
MASS | Mass
of moving rigid wall if G0 is
defined. (Real ≥ 0) |
|
VX, VY, VZ | Components of initial velocity if
G0 is
defined. (Real) |
Comments
- RWALL must be selected in the subcase with RWALL=SID or by RWALADD. It can only be selected in geometric nonlinear analysis subcases which are defined by an ANALYSIS=EXPDYN subcase entry.
- Nodal thickness of rigid wall secondary nodes is not taken into account.
- IFILT defines the method for
computing the friction filtering coefficient. Friction filtering is only available for a
sliding rigid wall. If IFILT ≠ 0, the tangential
friction forces in each secondary node in contact are filtered using a simple
rule:
(1) Where,- FT
- Tangential force
- F′T
- Tangential force at time t
- F′T-1
- Tangential force at time t-1
- α
- Filtering coefficient
IFILT=1 - α=FFAC
IFILT = 2 - α = 2πdt * freq, where dt = time step, and freq = FFAC
IFILT = 3 - α = 2π / N, with 1/freq = T = N * dt, and N = FFAC
- Surface input type:
- Type
- Description
- PLANE
- MM1 defines the normal direction.
- CYL
- MM1 defines the axis of the cylinder.
- SPHER
- M is the center of the sphere.
- PARAL
- MM1 and MM2 define the parallelogram with the normal as cross product MM1 x MM2.
- This card is represented as a rigid wall in HyperMesh.