Command manual

Command list

MAT_MULTILAYER_ORTHOTROPIC

Material properties
*MAT_MULTILAYER_ORTHOTROPIC
"Optional title"
mid, $\rho$, $E_1$, $E_2$, $G_{12}$, $\nu_{12}$
$E_3$, $G_{13}$, $G_{23}$, $\nu_{13}$, $\nu_{23}$, $\epsilon_t$, $\epsilon_c$, erode
ndir, $\alpha_1$, ..., $\alpha_7$
$c$

Parameter definition

VariableDescription
mid Unique material identification number
$\rho$ Density
$E_1$ In-plane Young's modulus (0-direction)
$E_2$ In-plane Young's modulus (othogonally to 0-direction)
$G_{12}$ In-plane shear modulus
$\nu_{12}$ Poisson's ratio
$E_3$ Young's modulus in transverse direction
$G_{13}$ Transverse shear modulus
$G_{23}$ Transverse shear modulus
$\nu_{13}$ Poisson's ratio
$\nu_{23}$ Poisson's ratio
$\epsilon_t$ Tensile failure strain in fiber direction
$\epsilon_c$ Compressive failure strain in fiber direction
erode Element erosion flag
options:
0 $\rightarrow$ failed elements keep the bulk stiffness
1 $\rightarrow$ failed elements are eroded
2 $\rightarrow$ node splitting
ndir Number of fiber directions (up to 7)
$\alpha_1$, ..., $\alpha_7$ Fiber directions for failure check (angles relatively the 0-direction)
$c$ Strain rate sensitivity parameter

Description

This is an orthototropic composite model where failure can occur in up to 7 different fiber directions. The stress can be expressed as:

$\mathbf{\sigma} = \mathbf{L} : \mathbf{\epsilon} + c \dot{\mathbf{\epsilon}}$

where $\mathbf{L}$ is the tangential stiffness of the material (fourth order tensor). Failure occurs if the tensile or compressive strain in a fiber direction exceeds $\epsilon_t$ and $\epsilon_c$, respectively. All deviatoric stresses are set to zero at fiber failure.

Initial fiber directions need to be defined using either INITIAL_MATERIAL_DIRECTION, INITIAL_MATERIAL_DIRECTION_VECTOR or INITIAL_MATERIAL_DIRECTION_WRAP.