*MAT_026 (HONEYCOMB)

LS-DYNA Input Interface KeywordThis keyword defines an orthotropic compressible honeycomb material.

Format

Field	Contents	SI Unit Example
`mat_ID`	Material identifier (Integer)
$ρ_{i}$	Initial density (Real)	$[\frac{kg}{m^{3}}]$
`LC1`	Stress vs either relative volume or volumetric strain in direction 1 (Real)	$[Pa]$
`LC2`	Stress vs either relative volume or volumetric strain in direction 2 (Real)	$[Pa]$
`LC3`	Stress vs either relative volume or volumetric strain in direction 3 (Real)	$[Pa]$
`LCS`	Shear stress vs either relative volume or volumetric strain (Real)	$[Pa]$
`LC12`	Shear stress vs shear strain in direction 12 (Real)	$[Pa]$
`LC23`	Shear stress vs shear strain in direction 23 (Real)	$[Pa]$
`LC31`	Shear stress vs shear strain in direction 31	$[Pa]$
`LCSR`	Scaling coefficients for stress vs strain rate (Real)
`LC31`	Shear stress vs either relative volume or volumetric strain in direction 31 (Real)	$[Pa]$
`E11`	Young modulus in direction 1 (Real)	$[Pa]$
`E11`	Young modulus in direction 2 (Real)	$[Pa]$
`E11`	Young modulus in direction 3 (Real)	$[Pa]$
`G12`	Shear modulus in direction 12 (Real)	$[Pa]$
`G23`	Shear modulus in direction 23 (Real)	$[Pa]$
`G32`	Shear modulus in direction 32 (Real)	$[Pa]$
`AOPT`	Choice of orthotropy axis = 2 orthotropy axis determined by `A1`, `A2`, `A3`, `D1`, `D2`, `D3` < 0 `AOPT` is number of DEFINE_COORDINATE_ to define orthotropic system (Integer)
`A1`, `A2`, `A3`	First orthotropy direction vector for `AOPT`=2 (Real)
`D1`, `D2`, `D3`	With `A1`, `A2`, `A3` determines 12 plane of orthotropy for `AOPT`=2 (Real)
`TSEF`	Tensile strain to failure (Real)
`SSEF`	Shear strain to failure (Real)

This material law maps to /MAT/LAW50 (VISC_HONEY) and /PROP/TYPE6 (SOL_ORTH).
The material is fully compressible. All degrees of freedom are decoupled.
Curves in directions 1, 2, 3 are engineering stresses as functions of either volumetric strain, which means the first abscissa point is negative or relative volume (the first abscissa point is positive).
Positive stresses and strains correspond to compression in direction 1, 2, 3.
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.