Command manual

Command list

INITIAL_MATERIAL_DIRECTION_WRAP

Initial conditions
*INITIAL_MATERIAL_DIRECTION_WRAP
"Optional title"
coid, entype, enid
$x_0$, $y_0$, $z_0$, $\hat{u}_x$, $\hat{u}_y$, $\hat{u}_z$, $\alpha$

Parameter definition

VariableDescription
coid Command ID
entype Entity type
options: P, PS
enid Entity ID
$x_0$, $y_0$, $z_0$ Coordinate used for definition of the ply location
$\hat{u}_x$, $\hat{u}_y$, $\hat{u}_z$ Vector used for definition of the ply orientation
$\alpha$ Angle used for definition of fiber direction

Description

This command is used to define local material directions in anisotropic materials such as fiber composites. The user defines the location and orientation of a "ply" in space. This ply is then wrapped around the component.

Note that models with more than one element in thickness direction require special consideration. For such models the wrapping algorithm requires a mesh with elements that are larger in-plane than in thickness direction.

The ply first needs to be projected onto the component. This projection generates intermediate in-plane directions $\bar{\mathbf x}$ and $\bar{\mathbf y}$.

$\displaystyle{ \bar{\mathbf y} = \frac{\hat{\mathbf z} \times \hat{\mathbf u}}{\vert \hat{\mathbf z} \times \hat{\mathbf u} \vert}}$
$\displaystyle{ \bar{\mathbf x} = \bar{\mathbf y} \times \hat{\mathbf z}}$

where $\hat{\mathbf z}$ is the local face surface normal direction. The local fiber direction $\hat{\mathbf x}$ and the orthogonal direction $\hat{\mathbf y}$ can now be defined by rotating the intermediate directions with the angle $\alpha$.

$\displaystyle{ \hat{\mathbf x} = \cos (\alpha) \bar{\mathbf x} + \sin (\alpha) \bar{\mathbf y}}$
$\displaystyle{ \hat{\mathbf y} =-\sin (\alpha) \bar{\mathbf x} + \cos (\alpha) \bar{\mathbf y}}$
Definition of fiber direction
Definition of fiber direction