# structure liner property command

Syntax

structure liner property keyword ... <range>

Assigns a property to elements in the range. The element can have isotropic, orthotropic, or anisotropic elastic material properties. Note that if the liner is embedded, then coupling spring properties must be entered separately on side 2. The following properties are available:

density f

density (needed if dynamic mode or gravity is active)

thickness f

liner thickness

thermal-expansion f

thermal expansion coefficient

anisotropic-membrane f1 f2 f3 f4 f5 f6

anisotropic membrane material properties {$$c^{\prime}_{11}, c^{\prime}_{12}, c^{\prime}_{13}, c^{\prime}_{22}, c^{\prime}_{23}, c^{\prime}_{33}$$} $$[F/L^2]$$, which define membrane material-stiffness matrices $$[Eʹ_m]$$ and $$[Eʹ_b]$$, respectively, in the material directions $$x'$$, $$y'$$, $$z'$$

anisotropic-bending f1 f2 f3 f4 f5 f6

anisotropic bending material properties {$$c^{\prime}_{11}, c^{\prime}_{12}, c^{\prime}_{13}, c^{\prime}_{22}, c^{\prime}_{23}, c^{\prime}_{33}$$} $$[F/L^2]$$, which define bending material-stiffness matrices $$[Eʹ_m]$$ and $$[Eʹ_b]$$, respectively, in the material directions $$x'$$, $$y'$$, $$z'$$.

material-x v

specify the vector v whose projection onto the geogrid surface defines the $$xʹ$$-axis of the material coordinate system. The material directions correspond with the principal directions of orthotropy (for more information, see below).

isotropic f1 f2

isotropic material properties: $$E$$ and $$v$$ where $$E$$ is Young’s modulus $$[F/L^2]$$ and $$v$$ is Poisson’s ratio

orthotropic-membrane f1 f2 f3 f4

orthotropic membrane material properties {$$c^{\prime}_{11}, c^{\prime}_{12}, c^{\prime}_{22}, c^{\prime}_{33}$$} $$[F/L^2]$$, which define membrane material-stiffness matrices $$[Eʹ_m]$$ and $$[Eʹ_b]$$, respectively, in the material directions $$x$$‘, $$y$$‘, $$z$$‘.

orthotropic-bending f1 f2 f3 f4

orthotropic bending material properties {$$c^{\prime}_{11}, c^{\prime}_{12}, c^{\prime}_{22}, c^{\prime}_{33}$$} $$[F/L^2]$$, which define bending material-stiffness matrices $$[Eʹ_m]$$ and $$[Eʹ_b]$$, respectively, in the material directions $$x$$‘, $$y$$‘, $$z$$‘.

slide b

large-strain sliding flag

slide-tolerance f

large-strain sliding tolerance

coupling-yield-normal f

normal coupling spring tensile strength (stress units)

coupling-yield-normal-2 f

normal coupling spring tensile strength on side 2 (stress units)

coupling-stiffness-normal f

normal coupling spring stiffness per unit area

coupling-stiffness-normal-2 f

normal coupling spring stiffness per unit area on side 2

coupling-stiffness-shear f

shear coupling spring stiffness per unit area

coupling-stiffness-shear-2 f

shear coupling spring stiffness per unit area on side 2

coupling-cohesion-shear f

shear coupling spring cohesion (stress unit)

coupling-cohesion-shear-2 f

shear coupling spring cohesion (stress unit) on side 2

coupling-cohesion-shear-residual f

shear coupling spring residual cohesion

coupling-cohesion-shear-residual-2 f

shear coupling spring residual cohesion on side 2

coupling-friction-shear f

shear coupling spring friction angle (degrees)

coupling-friction-shear-2 f

shear coupling spring friction angle (degrees) on side 2

effective b

effective stress flag (default to on). If off, then pore-pressures are not removed from the stress normal to the liner when determining shear failure limits.

Further information on the material-x keyword

The material coordinate system, $$xʹ$$, $$yʹ$$, $$zʹ$$, defines the orthotropic and anisotropic properties and satisfies the following conditions: 1) $$xʹ$$ is the projection of the given vector onto the surface; 2) $$zʹ$$ is normal to the surface and aligned with the $$z$$-axis of the shell-type element coordinate system; and 3) $$yʹ$$ = $$zʹ$$ × $$xʹ$$. The material coordinate system moves with the shell surface during large-strain updates, which means that the relative orientations of this system and the element local system do not change (the angle $$β$$ in this figure does not change). If the material $$x$$-vector is not specified, then the $$xʹ$$-axis will be aligned with the $$x$$-axis of the structural element local coordinate system.

The material coordinate system can be queried with the command structure liner list property material-x and the FISH function struct.shell.beta. It can be visualized with the structural geometry plot item by choosing the corresponding System attribute.