DMGEVO

Bulk Data Entry Defines the damage evolution.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMGEVO DMGEVOID TYPE SHAPE FLAT
MMXFM ALPHA W1 W2 W3 X1
ALPHA_2 W1_2 W2_2 W3_2 X2
... ... ... ... ...

Example (Damage based on energy with power law mixing)

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMGEVO 24 COHENRG EXP
1 1.2 2.0 5.0 5.0

Example (Damage based on energy with B-K form mixing)

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMGEVO 57 COHENRG LIN
2 1.5 24.0 50.0

Example (Damage based on energy no mode mixing)

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMGEVO 57 COHENRG LIN
20.0

Example (Damage based on opening)

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMGEVO 1 COHDISP EXP
2.0 20.0

Example (Ductile damage based on displacement)

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMGEVO 1 DISP EXP
2.0 0.5

Example (Ductile damage based on energy)

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DMGEVO 1 ENERGY LIN
20.0

Definitions

Field Contents SI Unit Example
DMGEVOID Damage evolution identification number.

No default (Integer > 0)
TYPE Damage evolution type.
COHDISP
Damage index evaluated by displacement for cohesive elements.
COHENRG
Damage index evaluated by energy dissipated for cohesive elements.
DISP
Damage index evaluated by displacement for solid and shell elements (ductile damage).
ENERGY
Damage index evaluated by energy for solid and shell elements (ductile damage).

No default

SHAPE Profile shape of the traction-opening curve in the descending part.
LIN (Default)
Linear shape.
EXP
Exponential shape.
FLAT
Specifies the handling method for y-values outside the specified range of x-values.
=0 (Default)
If an x-value input is outside the range of x-values specified, the corresponding y-value look up is performed using linear extrapolation from the two start or two end points.
=FLAT or 1
If an x-value input is outside the range of x-values specified, the corresponding y-value is equal to the start or end points, respectively.
MMXFM Mode mixed form (only for TYPE = COHENRG).
Blank (Default)
Modes are not mixed.
1
Power law form.
2
Benzeggah-Kenane form.
ALPHA When TYPE = COHDISP with SHAPE = EXP, it is the exponent for the traction-separation curve.

When TYPE = COHENRG with MMXFM = 1, it is the exponent for the mixing formula.

When TYPE = COHENRG with MMXFM = 2, it is the mixing coefficient.

When TYPE = DISP with SHAPE = EXP, it is the exponent for the stress degrading curve.

When ENERGY with shape = EXP, it is the exponent for the stress degrading curve.

No default (Real > 0)
W1. W2, W3 Material curve parameters.
When TYPE=COHDISP/DISP, only W1 is required.
W1
The separation evaluated from damage initiation to failure.
W2 and W3
Must be blank.
When TYPE=COHENRG, the parameters are the energies that can be dissipated in pure normal and pure shear separation.
W1
Energy dissipated in Mode I.
W2
Energy dissipated in Mode II.
W3
Energy dissipated in Mode III.
When TYPE=COHENRG with MMXFM= Blank.
W1
Energy dissipated.
W2 and W3
Must be blank.
When TYPE=DISP
W1
Equivalent plastic displacement from damage initiation to failure. It can be measured as characteristic length multiplied by the plastic strain from the onset of damage initiation to damage fully developed (damage index = 1.0)
W2 and W3
Must be blank.
When TYPE=ENERGY
W1
Energy dissipated from damage initiation to failure. It can be measured as characteristic length multiplied by the area below the stress-strain curve from the onset of damage initiation.
W2 and W3
Must be blank.

No default (Real > 0)

 Unit of length for TYPE=COHDISP/DISP

Force/Length or Energy/Length2 for TYPE=COHENRG/ENERGY
ALPHA_i, W1_i, W2_i, W3_i The ALPHA, W1, W2 and W3 values corresponding to temperature Xi.

No default (Real > 0)
Xi Temperature values.

If the damage constants are temperature independent, X1 can be blank.

No default (Real)

Comments

  1. The material identification number should be unique for all MAT1, MAT2, MAT3, MAT8, MAT9, MGASK, MCOHE, MCOHED, DMGINI, and DMGEVO entries.
  2. The support information for damage evolution is:
    Analysis Types Criterion
    Nonlinear Static Analysis, Nonlinear Transient Analysis DISP, ENERGY, COHDISP, COHENRG
    Explicit Dynamic Analysis DISP, ENERGY
    Element Types Criterion
    Regular Shell and Solid Elements DISP, ENERGY
    Cohesive Elements COHDISP, COHENRG
  3. Characteristic length is calculated element by element in ductile damage analysis. It is related to element size.
  4. For additional information about cohesive elements, refer to Cohesive Zone Modeling in the User Guide.