/FAIL/SPALLING

Block Format Keyword Describes the Spalling and Johnson-Cook failure model.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/FAIL/SPALLING/mat_ID/unit_ID
D1 D2 D3 D4 D5
ε ˙ 0 Pmin Ifail_so        
Optional Line
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
fail_ID                  

Definition

Field Contents SI Unit Example
mat_ID Material identifier

(Integer, maximum 10 digits)

 
unit_ID Unit Identifier

(Integer, maximum 10 digits)

 
D1 1st parameter.

(Real)

 
D2 2nd parameter.

(Real)

 
D3 3rd parameter.

(Real)

 
D4 4th parameter.

(Real)

 
D5 5th parameter.

(Real)

 
ε ˙ 0 Reference strain rate.

(Real)

[ 1 s ]
Pmin Pressure cutoff.

(Real < 0)

[ Pa ]
Ifail_so Failure model flag.
= 1
For each integration point, spalling is allowed: once spalling is detected (P = Pmin), the deviatoric stress is set to zero and pressure is required to be compressive.
= 2
For each integration point, spalling is allowed and solid element is deleted, if D = Δ ε p ε f 1 for one integration point or layer.
= 3
For each integration point, spalling is allowed and the deviatoric element stress tensor vanishes, if D = Δ ε p ε f 1 .
= 4
Solid element is deleted, if D = Δ ε p ε f 1 or P = Pmin for one integration point.

(Integer)

 
fail_ID Failure criteria identifier. 3

(Integer, maximum 10 digits)

 

Comments

  1. This failure model is available for Solid only.
  2. In this model two models are combined. The first one is the Johnson-Cook failure model, and the second one is the Spalling model (Spall is detected if (P = Pmin), the deviatoric stress is set to zero and pressure is required to be compressive).(1)
    ε f = [ D 1 + D 2 exp ( D 3 σ * ) ] [ 1 + D 4 ln ( ε ˙ * ) ] [ 1 + D 5 T * ]
    Where,
    σ * = σ m σ V M
    ε ˙ * = ε ˙ ε ˙ 0
    T*
    Is computed in the material law, if this one is thermo plastic, like /MAT/LAW4 (HYD_JCOOK).
  3. The fail_ID is used with /STATE/BRICK/FAIL and /INIBRI/FAIL. There is no default value. If the line is blank, no value will be output for failure model variables in the /INIBRI/FAIL (written in .sta file with /STATE/BRICK/FAIL option).