Advanced material properties

Elastic and isotropic material properties are assumed for many finite element analyses. The material stiffness (Young's Modulus) is assumed to be constant and equal in every strain direction. However, there are situations where you must consider more advanced material properties and behavior. The following list describes the available advanced material types.

Material Types that are supported for simulation studies

• Nonlinear materials: This type of material has a non-constant stiffness. The slope of the stress-strain curve decreases considerably once the stress exceeds the yield strength of the material. In addition, work hardening can occur in the plastic strain region (that is, the yield strength can increase as the material is plastically strained further).

  Note: Materials typically assumed to be linear for finite element analyses (such as isotropic metals) are actually nonlinear. The difference is that you can assume elastic properties when stresses and deformations remain sufficiently small. To quantify the behavior for applications where the yield strength is exceeded, you must perform a nonlinear analysis and define nonlinear material properties.

• Temperature-Dependent materials: Thermal conductivity, expansion coefficient, specific heat, stiffness, and strength vary with temperature. If your analysis involves temperature ranges for which these properties will vary considerably, you should define temperature-dependent material properties. For example, a structural member will fail at a much smaller load if its temperature is say 1200° F, as opposed to room temperature.

• Hyperelastic materials: A hyperelastic material model, such as Mooney-Rivlin, is needed to accurately simulate the behavior of rubberlike materials. The Mooney-Rivlin material model defines the behavior of hyperelastic materials based on three variables (A01, A10, and D1).

See the links at the bottom of the page for topics detailing each of these material types.