2021

2021

*MAT_081 (PLASTICITY_WITH_DAMAGE)

LS-DYNA Input Interface KeywordThis keyword defines an isotropic elasto-plastic material using tabulated stress vs plastic strain input for different strain rates and simple damage model.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
MAT_081 or MAT_PLASTICITY_WITH_DAMAGE
`mat_ID`	$ρ_{i}$	`E`	`ν`	`SIGY`	`ETAN`	`FAIL`
`C`	`P`	`LCSS`	`LCSR`	`EPS_max`	`VP`		`Numint`
`EPS1`	`EPS2`	`EPS3`	`EPS4`	`EPS5`	`EPS6`	`EPS7`	`EPS8`
`ES1`	`ES2`	`ES3`	`ES4`	`ES5`	`ES6`	`ES7`	`ES8`

Definition

Field	Contents	SI Unit Example
`mat_ID`	Material Identifier (Integer)
$ρ_{i}$	Initial density (Real)	$[\frac{kg}{m^{3}}]$
`E`	Young’s modulus (Real)	$[Pa]$
`v`	Poisson’s ratio Default = 0 (Real)
`SIGY`	Yield stress, ignored if `LCSS` > 0 or stress-strain values `EPS1`-`EPS8`, `ES1`-`ES8` specified (Real)	$[Pa]$
`ETAN`	Plastic hardening modulus, not used if `LCSS` > 0 (Real)	$[Pa]$
`FAIL`	Plastic strain for material softening (Real)
`C`	Strain rate coefficient (Real)	$[\frac{1}{s}]$
`P`	Strain rate exponent (Real)
`LCSS`	Stress vs plastic strain curve or table identifier (Integer)	$[Pa]$
`LCSR`	Curve identifier defining the scaling coefficient for the stress-strain curve for a corresponding strain rate (Integer)
`EPS_max`	Plastic strain for element deletion (Real)
`VP`	Strain rate type flag: 0 Total strain rate 1 Plastic strain rate (Integer)
`EPS1-EPS8`	Plastic strain data points (Real)
`ES1`-`ES8`	Yield stress data points (Real)	$[Pa]$

Comments

This keyword maps to /MAT/LAW36 (PLAS_TAB) or /MAT/LAW44 (COWPER) according to the input.
The option “_TITLE” can be added to the end of this keyword. When “_TITLE” is included, an extra 80 character long line is added after the keyword input line which allows an entity title to be defined.