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!DAMPING

Element-wise Rayleigh damping coefficients. Specified inside a !MATERIAL block.

For elements belonging to material \(i\), the damping matrix \(C_i\) is evaluated from the material's mass matrix \(M_i\) and tangent stiffness matrix \(K_i\) as

\[ C_i = R_m M_i + R_k K_i \]

and assembled into the global damping matrix. The global Rayleigh damping coefficients (ray_m, ray_k) given on the !DYNAMIC card are ignored for any material that specifies !DAMPING; the !DAMPING values take precedence for those materials.

This card is effective only for implicit dynamic analysis (!SOLUTION, TYPE=DYNAMIC with the Newmark-β method). It is not referenced by static, eigenvalue, frequency response, or explicit dynamic analyses.

Parameter

TYPE = RAYLEIGH : Rayleigh damping (default; currently the only supported model)
Parameter Name Attributions Contents
TYPE P Damping model. Optional. Currently only RAYLEIGH is supported (default)

** 2nd line **

(2nd line) Rm, Rk
Variable Attributions Contents
Rm R Proportional coefficient \(R_m\) for mass matrix (default: 0.0)
Rk R Proportional coefficient \(R_k\) for stiffness matrix (default: 0.0)

Example

!MATERIAL, NAME=M1
!ELASTIC
 210000.0, 0.3
!DENSITY
 7.85e-9
!DAMPING, TYPE=RAYLEIGH
 0.5, 1.0e-3
  • !DYNAMIC: global Rayleigh damping coefficients
  • !MATERIAL: general form of the material card