Specifying elastic material properties

From the menu bar in the Edit Material dialog box, select MechanicalElasticityElastic.
(For information on displaying the Edit Material dialog box, see Creating or editing a material.)
From the Type field, choose the type of data you will supply to specify the elastic material properties.
- Choose Isotropic to specify isotropic elastic properties, as described in Defining isotropic elasticity.
- Choose Engineering Constants to specify orthotropic elastic properties by giving the engineering constants, as described in Defining orthotropic elasticity by specifying the engineering constants.
- Choose Lamina to specify orthotropic elastic properties in plane stress, as described in Defining orthotropic elasticity in plane stress.
- Choose Orthotropic to specify orthotropic elastic properties directly, as described in Defining orthotropic elasticity by specifying the terms in the elastic stiffness matrix.
- Choose Anisotropic to specify anisotropic elastic properties, as described in Defining fully anisotropic elasticity.
- Choose Traction to specify orthotropic elastic properties for warping elements, as described in Defining orthotropic elasticity for warping elements, or to define uncoupled elastic properties for cohesive elements, as described in Defining elasticity in terms of tractions and separations for cohesive elements.
- Choose Coupled Traction to specify coupled elastic properties for cohesive elements, as described in Defining elasticity in terms of tractions and separations for cohesive elements.
- Choose Shear to specify a linear isotropic deviatoric material model. For more information, see Deviatoric behavior.
To define behavior data that depend on temperature, toggle on Use temperature-dependent data.
A column labeled Temp appears in the Data table.
To define behavior data that depend on field variables, click the arrows to the right of the Number of field variables field to increase or decrease the number of field variables.
Field variable columns appear in the Data table.
If you are defining the elastic behavior of a viscoelastic material, click the arrow to the right of the Moduli time scale (for viscoelasticity) field to specify either long-term or instantaneous elastic response.
Toggle on No compression if you want to modify the elastic material response such that compressive stress cannot be generated. For details, see No compression or no tension.
Toggle on No tension if you want to modify the elastic material response such that tensile stress cannot be generated. For details, see No compression or no tension.
Enter the material properties in the Data table.
- For Isotropic data, enter the Young's modulus, E, and Poisson's ratio, $ν$ .
- For Engineering Constants data, enter the generalized Young's moduli in the principal directions, $E_{1}$ , $E_{2}$ , $E_{3}$ ; the Poisson's ratios in the principal directions, $ν_{12}$ , $ν_{13}$ , $ν_{23}$ ; and the shear moduli in the principal directions, $G_{12}$ , $G_{13}$ , $G_{23}$ .
- For Lamina data, enter the Young's moduli, $E_{1}$ , $E_{2}$ ; the Poisson's ratio, $ν_{12}$ ; and the shear moduli, $G_{12}$ , $G_{13}$ , $G_{23}$ . The $G_{13}$ and $G_{23}$ shear moduli are needed to define transverse shear behavior in shells.
- For Orthotropic data, enter the 9 elastic stiffness parameters: $D_{1111}$ , $D_{1122}$ , etc. (units of FL⁻²).
- For Anisotropic data, enter the 21 elastic stiffness parameters: $D_{1111}$ , $D_{1122}$ , etc. (units of FL⁻²).
- For Traction data, your entries depend on the element type that you are modeling.
  - For solid cross-section Timoshenko beam elements modeled with warping elements, enter the Young's modulus, $E$ , and the shear moduli in the material directions, $G_{1}$ and $G_{2}$ .
  - For cohesive elements with uncoupled traction, enter the elastic modulus in the normal direction and the two local shear directions, $E_{n n}$ , $E_{s s}$ , and $E_{t t}$ .
- For Coupled Traction data, enter the six elastic moduli: $E_{n n}$ , $E_{s s}$ , $E_{t t}$ , $E_{n s}$ , $E_{n t}$ , and $E_{s t}$ .
- For Shear data, enter the Shear Modulus.
To define the plane stress orthotropic failure measures for the material, if desired, click Suboptions. For details, see the following sections:
- Defining stress-based failure measures for an elastic model”
- Defining strain-based failure measures for an elastic model”
Click OK to create the material and to close the Edit Material dialog box. Alternatively, you can select another material behavior to define from the menus in the Edit Material dialog box (see Browsing and modifying material behaviors, for more information).