/LOAD/CENTRI

Block Format Keyword Apply a centrifugal force on a set of nodes according a body rotational velocity around the defined direction.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/LOAD/CENTRI/load_ID/unit_ID
load_title
fct_IDT Dir frame_ID sens_ID grnod_ID Ivar Ascalex Fscaley

Definitions

Field Contents SI Unit Example
load_ID Load identifier

(Integer, maximum 10 digits)

 
unit_ID Unit Identifier

(Integer, maximum 10 digits)

 
load_title Load title

(Character, maximum 100 characters)

 
fct_IDT Time function identifier, giving the rotational velocity ω versus time.

(Integer)

 
Dir Direction of rotation (input XX, YY or ZZ)

(Text)

 
frame_ID Frame identifier
= 0
Rotation is expressed in global reference system
0
Rotation is expressed with respect to the frame.

(Integer)

 
sens_ID Sensor identifier.

(Integer)

 
grnod_ID Node group to which the load is applied.

(Integer)

 
Ivar Flag to disregard variation of velocity with respect to time, for the calculation of the force.
= 1 (Default)
Variation of velocity is not taken into account.
= 2
Variation of velocity is taken into account.

(Integer)

 
Ascalex Abscissa scale factor.

Default = 1.0 (Real)

[ s ]
Fscaley Ordinate scale factor.

Default = 1.0 (Real)

[ rad s ]

Comments

  1. A force is computed corresponding to a body rotational velocity around the direction Dir of the global reference system if frame_ID = 0, or the reference system defined by the frame if frame_ID ≠ 0.
  2. This option is not a kinematic condition (velocity of the nodes is not specified).
  3. If frame_ID = 0, the force applied to the node of mass m , at location M is computed as:(1)
    F = m ( d ω d t O M + ω ω O M )

    If Ivar = 1:

    d ω d t O M is not taken into account.(2)
    F = m ( ω ω O M )
  4. If frame_ID0, the force applied to a node is computed as: (3)
    F = f r + f e + f c
    Driving force:(4)
    f e = m ( γ ( A ) + ( d Ω ( R ' / R ) d t ) A M + Ω ( R ' / R ) ( Ω ( R ' / R ) A M ) ) MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaCOzamaaBa aaleaacaWGLbaabeaakiabg2da9iaad2gadaqadaqaaiaaho7acaGG OaGaamyqaiaacMcacqGHRaWkdaqadaqaamaalaaabaGaamizaiaahM 6adaWgaaWcbaGaaiikaiaadkfacaGGNaGaai4laiaadkfacaGGPaaa beaaaOqaaiaadsgacaWG0baaaaGaayjkaiaawMcaaiabgEIizlaahg eacaWHnbGaey4kaSIaaCyQdmaaBaaaleaacaGGOaGaamOuaiaacEca caGGVaGaamOuaiaacMcaaeqaaOGaey4jIK9aaeWaaeaacaWHPoWaaS baaSqaaiaacIcacaWGsbGaai4jaiaac+cacaWGsbGaaiykaaqabaGc cqGHNis2caWHbbGaaCytaaGaayjkaiaawMcaaaGaayjkaiaawMcaaa aa@6050@
    Coriolis force:(5)
    f c = m ( 2 Ω ( R ' / R ) v ( M ) / R ' ) MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaCOzamaaBa aaleaacaWGJbaabeaakiabg2da9iaad2gadaqadaqaaiaaikdacaWH PoWaaSbaaSqaaiaacIcacaWGsbGaai4jaiaac+cacaWGsbGaaiykaa qabaGccqGHNis2caWH2bGaaiikaiaad2eacaGGPaWaaSbaaSqaaiaa c+cacaWGsbGaai4jaaqabaaakiaawIcacaGLPaaaaaa@4954@
    Relative force:(6)
    f r = m ( d ω d t A M + ω ω A M )

    If Ivar = 1:

    d ω d t A M is not taken into account in relative force.

    (7)
    f r = m ( ω ω A M )
    Where,
    R
    Global reference system
    R'
    Reference system defined by the frame
    A
    Origin of the frame
    M
    A point of the defined group of node
    Ω ( R ' / R )
    Rotational velocity of the frame with respect to the global reference system
    ω
    Rotational velocity defined by the time function