16.2. Elastic Orthotropic Damage Model

BEGIN PARAMETERS FOR MODEL ELASTIC_ORTHOTROPIC_DAMAGE
  #
  # Elastic constants
  #
  YOUNGS MODULUS = <real>
  POISSONS RATIO = <real>
  SHEAR MODULUS  = <real>
  BULK MODULUS   = <real>
  LAMBDA         = <real>
  #
  # Required parameters
  #
  E11    = <real>
  E22    = <real>
  E33    = <real>
  NU12   = <real>
  NU13   = <real>
  NU23   = <real>
  G12    = <real>
  G13    = <real>
  G23    = <real>
  ALPHAD = <real>
  BETAD  = <real>
  GAMMA0 = <real>
  J1     = <real> j1
  J2     = <real> j2
  J3     = <real> j3
  CN11   = <real> cn11
  CN22   = <real> cn22
  CN33   = <real> cn33
  CS12   = <real> cs12
  CS13   = <real> cs13
  CS23   = <real> cs23
  COORDINATE SYSTEM = <string> coordinate_system_name
  #
  # Optional parameters
  #
  ANGLE_1_ABSCISSA = <real>angle_1_abscissa
  ANGLE_2_ABSCISSA = <real>angle_2_abscissa
  ANGLE_3_ABSCISSA = <real>angle_3_abscissa
  ROTATION_AXIS_1  = <real>rotation_axis_1
  ROTATION_AXIS_2  = <real>rotation_axis_2
  ROTATION_AXIS_3  = <real>rotation_axis_3
  ANGLE_1_FUNCTION = <string>angle_1_function_name
  ANGLE_2_FUNCTION = <string>angle_2_function_name
  ANGLE_3_FUNCTION = <string>angle_3_function_name
  E11 FUNCTION    = <string>func_name
  E22 FUNCTION    = <string>func_name
  E33 FUNCTION    = <string>func_name
  NU12 FUNCTION   = <string>func_name
  NU13 FUNCTION   = <string>func_name
  NU23 FUNCTION   = <string>func_name
  G12 FUNCTION    = <string>func_name
  G13 FUNCTION    = <string>func_name
  G23 FUNCTION    = <string>func_name
END [PARAMETERS FOR MODEL ELASTIC_ORTHOTROPIC_DAMAGE]

The elastic orthotropic damage model is an empirically based constitutive relation that is useful for modeling polymer matrix composite structures. Refer to SAND2013-7257 for a full description of the material model theory and usage.

The command block for an elastic orthotropic damage material starts with the line:

BEGIN PARAMETERS FOR MODEL ELASTIC_ORTHOTROPIC_DAMAGE

and terminates with the line:

END [PARAMETERS FOR MODEL ELASTIC_ORTHOTROPIC_DAMAGE]

In the above command block, the required inputs are: two of the five general elastic material constants, directional properties, and the coordinate system. The following is a brief description of each input.

The density of the material is defined with the DENSITY command line.
The Biot’s coefficient of the material is defined with the BIOTS COEFFICIENT command line.
Any two of the following elastic constants are required:

-[textbullet] Young’s modulus is defined with the YOUNGS MODULUS command line. -[textbullet] Poisson’s ratio is defined with the POISSONS RATIO command line. -[textbullet] The bulk modulus is defined with the BULK MODULUS command line. -[textbullet] The shear modulus is defined with the SHEAR MODULUS command line. -[textbullet] Lambda is defined with the LAMBDA command line.
The directional moduli \(E_{11}\), \(E_{22}\), and \(E_{33}\) are defined with the E11, E22, and E33 command lines.
The directional Poisson’s ratios \(\nu_{12}\), \(\nu_{13}\), and \(\nu_{23}\) are defined with the NU12, NU13, and NU23 command lines.
The directional shear moduli \(G_{12}\), \(G_{13}\), and \(G_{23}\) are defined with the G12, G13, and G23 command lines.
The specification of the principal material directions begins with the selection of a user specified coordinate system given by the COORDINATE SYSTEM command line (see below).
The damage surface evolution terms are given with the ALPHAD and BETAD command lines.
The initial damage threshold is defined with the GAMMA0 command line.
The directional damage surface coefficients with the J1, J2 and J3 command lines.
The directional normal crack closure coefficients defined with the CN11, CN22 and CN33 command lines.
The directional shear crack closure coefficients are defined with the CS12, CS13 and CS23 command lines.
For material orientation definition instructions see the Sierra/SM User Manual.

Warning

The ELASTIC_ORTHOTROPIC_DAMAGE model has not been tested in conjunction with the control stiffness implicit solver block.