/DAMP

Engine Keyword Used to modify the Rayleigh mass and stiffness damping coefficients defined using the Starter /DAMP option.

Format 1 (Short Format)

/DAMP/damp_ID

α β

Format 2 (Full Format)

/DAMP/damp_ID

α x    β x α y    β y α z   βz α xx    β xx α yy    β yy α zz    β zz MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcea qabeaajaaOcqaHXoqykmaaBaaaleaacaWG4baabeaakiaabccacaqG GaGaeqOSdi2aaSbaaSqaaiaadIhaaeqaaaGcbaqcaaQaeqySdeMcda WgaaWcbaGaamyEaaqabaGccaqGGaGaaeiiaiabek7aInaaBaaaleaa caWG5baabeaaaOqaaKaaGkabeg7aHPWaaSbaaSqaaiaadQhaaeqaaO GaaeiiaiaabccacqaHYoGycaWG6baabaqcaaQaeqySdeMcdaWgaaWc baGaamiEaiaadIhaaeqaaOGaaeiiaiaabccacqaHYoGydaWgaaWcba GaamiEaiaadIhaaeqaaaGcbaqcaaQaeqySdeMcdaWgaaWcbaGaamyE aiaadMhaaeqaaOGaaeiiaiaabccacqaHYoGydaWgaaWcbaGaamyEai aadMhaaeqaaaGcbaqcaaQaeqySdeMcdaWgaaWcbaGaamOEaiaadQha aeqaaOGaaeiiaiaabccacqaHYoGydaWgaaWcbaGaamOEaiaadQhaae qaaaaaaa@6C28@

Definition

Field Contents SI Unit Example
damp_ID Identifier of damping option in Radioss Starter (/DAMP).  
α Mass damping coefficient used for all DOF. [ 1 s ]
β Stiffness damping coefficient used for all DOF. [ s ]
α x MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba qcaaQaeqySdeMcdaWgaaWcbaGaamiEaaqabaaaaa@3C1E@ Mass damping coefficient for translational degree of freedom (DOF) in x direction. [ 1 s ]
α y MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba qcaaQaeqySdeMcdaWgaaWcbaGaamiEaaqabaaaaa@3C1E@ Mass damping coefficient for translational DOF in y direction. [ 1 s ]
α z MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba qcaaQaeqySdeMcdaWgaaWcbaGaamiEaaqabaaaaa@3C1E@ Mass damping coefficient for translational DOF in z direction. [ 1 s ]
α xx MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba qcaaQaeqySdeMcdaWgaaqcbaAaaiaadIhacaWG4baabeaaaaa@3DBA@ Mass damping coefficient for rotational DOF in xx direction. [ 1 s ]
α y y MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba qcaaQaeqySdeMcdaWgaaqcbaAaaiaadIhacaWG4baabeaaaaa@3DBA@ Mass damping coefficient for rotational DOF in yy direction. [ 1 s ]
α z z MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba qcaaQaeqySdeMcdaWgaaqcbaAaaiaadIhacaWG4baabeaaaaa@3DBA@ Mass damping coefficient for rotational DOF in zz direction. [ 1 s ]
β x MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba GaeqOSdi2aaSbaaSqaaiaadIhaaeqaaaaa@3B6D@ Stiffness damping coefficient for translational DOF in x direction. [ s ]
β y MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba GaeqOSdi2aaSbaaSqaaiaadIhaaeqaaaaa@3B6D@ Stiffness damping coefficient for translational DOF in y direction. [ s ]
β z MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba GaeqOSdi2aaSbaaSqaaiaadIhaaeqaaaaa@3B6D@ Stiffness damping coefficient for translational DOF in z direction. [ s ]
β xx MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba GaeqOSdi2aaSbaaKqaGgaacaWG4bGaamiEaaqabaaaaa@3D09@ Stiffness damping coefficient for rotational DOF in xx direction. [ s ]
β y y MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba GaeqOSdi2aaSbaaKqaGgaacaWG4bGaamiEaaqabaaaaa@3D09@ Stiffness damping coefficient for rotational DOF in yy direction. [ s ]
β z z MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8akY=wiVeYth9vqqj=hEeuD0lXdbb a9frFj0=irFfea0lXdd9vqai=hGuQ8kuc9pgc9q8qqaq=dir=f0=yq aiVgFr0xfr=xfr=xb9adbaGaaiGadiWaamaaceGaaqaacaqbaaGcba GaeqOSdi2aaSbaaKqaGgaacaWG4bGaamiEaaqabaaaaa@3D09@ Stiffness damping coefficient for rotational DOF in zz direction. [ s ]

Comments

  1. Rayleigh α damping computation:(1)
    C = α M + β K MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaC4qaiabg2 da9iabeg7aHjaah2eacqGHRaWkcqaHYoGycaWHlbaaaa@3D95@
    (2)
    C i = α m i + β k i MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qamaaBa aaleaacaWGPbaabeaakiabg2da9iabeg7aHjaad2gadaWgaaWcbaGa amyAaaqabaGccqGHRaWkcqaHYoGycaWGRbWaaSbaaSqaaiaadMgaae qaaaaa@412A@
    (3)
    C crit = 4 m i k i
    (4)
    C i C crit = α 2 ω i + β ω i 2
    Where,
    C MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaC4qaaaa@36C3@
    Damping matrix
    M MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaC4qaaaa@36C3@
    Mass matrix
    K MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaC4qaaaa@36C3@
    Stiffness matrix
    α and β
    Coefficients
    C i MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qamaaBa aaleaacaWGPbaabeaaaaa@37D8@
    Nodal damping matrix
    m i MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qamaaBa aaleaacaWGPbaabeaaaaa@37D8@
    Nodal mass matrix
    k i MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qamaaBa aaleaacaWGPbaabeaaaaa@37D8@
    Nodal stiffness matrix
    C c r i t MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qamaaBa aaleaacaWGJbGaamOCaiaadMgacaWG0baabeaaaaa@3AB0@
    Critical damping
  2. This option can be used only if damping card (/DAMP) is defined in the Runname_0000.rad file.
  3. Arbitrary coefficients alpha and beta may be declared in the Runname_0000.rad file and modified when repeating the option in the Radioss Engine file Runname_run#.rad.