Question

ANSYS 中如何定义pzt材料的anisotropic elastic

Answer 1

各向异性材料的参数设定
在考虑材料的各向异性时，材料参数里Structural-Linear-Elastic-Anisotropic里，Anisotropic Elastic Matrix Options(Stiffness form)里的D11，D12....D66代表什么，该怎么填？多谢多谢！

见帮助里有，如下：

2.5.1.7. Anisotropic
This option (ANISO) allows for different stress-strain behavior in the material x, y, and z directions as well as different behavior in tension and compression (see Anisotropic Elastic Materials). A modified von Mises yield criterion is used to determine yielding. The theory is an extension of Hill's formulation as noted in the ANSYS, Inc. Theory Reference. This option is not recommended for cyclic or highly nonproportional load histories since work hardening is assumed. The principal axes of anisotropy coincide with the material (or element) coordinate system and are assumed not to change over the load history.

The material behavior is described by the uniaxial tensile and compressive stress-strain curves in three orthogonal directions and the shear stress-engineering shear strain curves in the corresponding directions. A bilinear response in each direction is assumed. The initial slope of the curve is taken as the elastic moduli of the material. At the specified yield stress, the curve continues along the second slope defined by the tangent modulus (having the same units as the elastic modulus). The tangent modulus cannot be less than zero or greater than the elastic modulus. Temperature dependent curves cannot be input. All values must be input as no defaults are defined. Input the magnitude of the yield stresses (without signs). No yield stress can have a zero value. The tensile x-direction is used as the reference curve for output quantities SEPL and EPEQ.

Initialize the stress-strain table with TB,ANISO. You can define up to 18 constants with TBDATA commands. The constants (C1-C18) entered on TBDATA commands (6 per command) are:

Constant Meaning (all units are Force/Area)
C1-C3 Tensile yield stresses in the material x, y, and z directions
C4-C6 Corresponding tangent moduli
C7-C9 Compressive yield stresses in the material x, y, and z directions
C10-C12 Corresponding tangent moduli
C13-C15 Shear yield stresses in the material xy, yz, and xz directions
C16-C18 Corresponding tangent moduli

See the TB command for a listing of the elements that can be used with this material option.

See Plastic Material Options in the ANSYS Structural Analysis Guide for more information on this material option.

I can't seem to find a resource or tutorial that explains how anisotropic material properties are used within ANSYS, especially in regards to FSI with CFX and blood vessels. The help files give a tiny bit of information on anisotropic, hyperelastic models; but I don't see it being enough to apply to more than a cylinder.

My thought was that I could create a single material model and then apply individual coordinate frames to each element of the vessel wall (which would ideally give a different component breakdown of the strain for each element), but I haven't figured a way to do that.

-Are users relying on a single coordinate frame for the entire model (it doesn't make sense for complicated geometry that doesn't follow an axis)?
-If not, how are the principle directions being determined (or material model modified) and applied?
-Is there a different, fully-coupled FSI, package that would make more sense to use for this problem?

Thanks in advance for any help,

Erick

追问

有点泛

Answer 2

建立材料模型里面，对话框右边依次选择Structural---Linear---Elastic---Anisotropic