/RWALL

Block Format Keyword Defines the following types of rigid walls: Infinite Plane, Infinite Cylinder, Sphere and Parallelogram.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/RWALL/type/rwall_ID/unit_ID
rwall_title
node_ID Slide grnd_ID1 grnd_ID2            
Dsearch fric ϕ ffac ifq  
If node_ID = 0
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
XM YM ZM        
If node_ID ≠ 0
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
Mass VX0 VY0 VZ0    
If type is Plane, Cyl, Paral.
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
XM1 YM1 ZM1        
If type is Paral.
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
XM2 YM2 ZM2          

Definitions

Field Contents SI Unit Example
type Rigid wall type keyword

(see table below)

  
rwall_ID Rigid wall identifier

(Integer, maximum 10 digits)

  
unit_ID Unit Identifier

(Integer, maximum 10 digits)

  
rwall_title Rigid wall title

(Character, maximum 100 characters)

  
node_ID Node identifier (moving rigid wall)

(Integer)

  
Slide Sliding flag.
= 0
Sliding
= 1
Tied
= 2
Sliding with friction

(Integer)

  
grnd_ID1 Node group defining slave nodes to be added to the rigid wall.

(Integer)

  
grnd_ID2 Node group defining slave nodes to be deleted from the rigid wall.

(Integer)

  
Dsearch Distance for slave search.

(Real)

 [ m ]
fric Friction.

(Real)

  
ϕ Diameter of the sphere.

(Real)

 [ m ]
ffac Filtering factor.

Default = 0.0 (Real)

  
ifq Filtering flag. 5

Default = 0 (Integer)

  
XM X coordinate of M

(Real)

  
YM Y coordinate of M

(Real)

  
ZM Z coordinate of M

(Real)

  
Mass Mass of the rigid wall. 8

If no mass is entered, the rigid wall will have a constant imposed velocity.

(Real)

 [ kg ]
VX0 Initial velocity in X direction

(Real)

 [ m s ] MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaamWaaeaada Wcaaqaaiaab2gaaeaacaqGZbaaaaGaay5waiaaw2faaaaa@39DE@
VY0 Initial velocity in Y direction

(Real)

 [ m s ] MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaamWaaeaada Wcaaqaaiaab2gaaeaacaqGZbaaaaGaay5waiaaw2faaaaa@39DE@
VZ0 Initial velocity in Z direction

(Real)

 [ m s ] MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaamWaaeaada Wcaaqaaiaab2gaaeaacaqGZbaaaaGaay5waiaaw2faaaaa@39DE@
XM1 X coordinate of M1

(Real)

  
YM1 Y coordinate of M1

(Real)

  
ZM1 Z coordinate of M1

(Real)

  
XM2 X coordinate of M2

(Real)

  
YM2 Y coordinate of M2

(Real)

  
ZM2 Z coordinate of M2

(Real)

  

Rigid Wall Type

Type
Description
PLANE
∞ ¯ plane
CYL
∞ ¯ Cylinder of diameter ϕ
SPHER
Sphere of diameter ϕ
PARAL
Parallelogram

Surface Input Type

Type
Description
PLANE
MM1 defines the normal direction

rwall_lagmul_plane2
CYL
MM1 defines the axis of the cylinder
rwall_cyl
SPHER
M is the center of the sphere
rwall_spher
PARAL
M M 1 and M M 2 define the parallelogram
rwall_paral

Comments

  1. The first input defines the rigid wall coordinates of one point M or a node_ID in case of moving rigid wall.
  2. The next input is the coordinate of a point M1 and possibly a point M2 (in case of a moving wall, M1 and M2 have the same motion as node_ID).
  3. The slave nodes to a rigid wall can be defined as a group of nodes and/or as nodes initially at a distance less than the distance (Dsearch) from the rigid wall.
  4. The friction filtering option is only available for a slide rigid wall with friction (Slide =2).
  5. Filtering flag ifg
    If ifq ≠ 0, the tangential (friction) forces in each slave node in contact are filtered using a simple rule:(1)
    F T = α ⋅ F ′ T + ( 1 − α ) ⋅ F ′ T − 1
    Where,
    F T
    Tangential force
    F ′ T
    Tangential force at time t
    F ′ T − 1
    Tangential force at time t-1
    α
    Filtering coefficient

    The flag ifq defines a method for filtering, α coefficient.

    If ifq =1, filtering coefficient is directly input by you: α = f f a c

    If ifq =2, α corresponds to a 3dB filtering level for user-defined frequency:(2)
    α = 2 π d t ⋅ f r e q MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8WjY=viVeYth9vqqj=hEeuD0xXdbb a9frFf0=yqFf0dbba91qpepeI8k8fiI+fsY=rqaqpepae9pg0Firpe pesP0xe9Fve9Fve9qapdbaGaaiGadiWaamaaceGaaqaacaqbaaGcba GaeqySdeMaeyypa0JaaGOmaiabec8aWjaadsgacaWG0bGaeyyXICTa amOzaiaadkhacaWGLbGaamyCaaaa@46D6@
    Where,
    dt MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamizaiaads haaaa@37D8@
    Time step
    freq MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzaiaadk hacaWGLbGaamyCaaaa@39B8@
    ffac
    If ifq =3, α corresponds to a 3dB filtering level for user-defined frequency (frequency defined in terms of time step number):(3)
    α = 2 π N

    with 1 f r e q = T = N d t , and N = f f a c MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOtaiabg2 da9iaadAgacaWGMbGaamyyaiaadogaaaa@3B73@

  6. The sphere (SPHER) and parallelogram (PARAL) are not infinite. For parallelograms, the normal is defined using:(4)
    M M 1 × M M 2

    and the diameter of the sphere is defined using ϕ .

  7. Nodal thickness of rigid wall slave nodes is not taken into account.
  8. For moving rigid walls with MASS=0 or blank, the rigid wall will have a constant imposed velocity and not an initial velocity.