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4.1.4.23 Solid Mixture
The material type for a constrained mixture of solids is “solid mixture”. This material describes a mixture of elastic solids that share the same reference configuration and same deformation gradient. It is a container for any combination of the unconstrained elastic materials described in Section 4.1.4↑.
<solid> | Container tag for unconstrained solid material |
The mixture may consist of any number of solids. The stress tensor for the solid mixture is the sum of the stresses for all the solids.
Material axes may be optionally specified within the <material> level, as well as within each <solid>. Within the <material> level, these represent the local element axes relative to the global coordinate system. Within the <solid>, they represent local material axes relative to the element. If material axes are specified at both levels, they are properly compounded to produce local material axes relative to the global coordinate system. Material axes specified in the <ElementData> section are equivalent to a specification at the <material> level: they correspond to local element axes relative to the global system.
Example:
<material id="1" type="solid mixture"> <solid type="neo-Hookean"> <E>1000.0</E> <v>0.45</v> </solid> <solid type="ellipsoidal fiber distribution"> <mat_axis type="vector"> <a>0.8660254, 0.5, 0</a> <d>0,0,1</d> </mat_axis> <ksi>5, 1, 1</ksi> <beta>2.5, 3, 3</beta> </solid> <solid type="ellipsoidal fiber distribution"> <mat_axis type="vector"> <a>0.8660254,-0.5, 0</a> <d>0,0,1</d> </mat_axis> <ksi>5, 1, 1</ksi> <beta>2.5, 3, 3</beta> </solid> </material>