# /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
${\stackrel{˙}{\epsilon }}_{0}$ Pmin Ifail_so
Optional Line
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
fail_ID

## Definitions

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)

${\stackrel{˙}{\epsilon }}_{0}$ Reference strain rate.

(Real)

$\left[\frac{\text{1}}{\text{s}}\right]$
Pmin Pressure cutoff.

(Real < 0)

$\left[\text{Pa}\right]$
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 $D=\sum \frac{\text{Δ}{\epsilon }_{p}}{{\epsilon }_{f}}\ge 1$ for one integration point or layer.
= 3
For each integration point, spalling is allowed and the deviatoric element stress tensor vanishes, if $D=\sum \frac{\text{Δ}{\epsilon }_{p}}{{\epsilon }_{f}}\ge 1$ .
= 4
Solid element is deleted, if $D=\sum \frac{\text{Δ}{\epsilon }_{p}}{{\epsilon }_{f}}\ge 1$ or P = Pmin for one integration point.

(Integer)

fail_ID Failure criteria identifier. 3

(Integer, maximum 10 digits)

${\epsilon }_{f}=\left[{D}_{1}+\text{​}{D}_{2} \mathrm{exp}\left({D}_{3}{\sigma }^{*}\right)\right]\left[1+{D}_{4}\mathrm{ln}\left({\stackrel{˙}{\epsilon }}^{*}\right)\right]\left[1+{D}_{5}{T}^{*}\right]$
${\sigma }^{*}=\frac{{\sigma }_{m}}{{\sigma }_{VM}}$
${\stackrel{˙}{\epsilon }}^{*}=\frac{\stackrel{˙}{\epsilon }}{{\stackrel{˙}{\epsilon }}_{0}}$