Anisotropic Materials¶
In addition to BurnMan’s standard materials, which have properties that are a function of pressure, temperature, and composition, BurnMan also includes classes for anisotropic elastic materials. These materials have elastic properties that depend on stress rather than pressure, or strain rather than volumetric compression.
Because most natural materials in the Earth can only withstand small deviatoric stresses before yielding or fracturing, the anisotropic materials in BurnMan have properties that are defined as a function of pressure, but these properties include those that describe the response of the material to small deviatoric stresses. Such properties include the full elastic tensor (isothermal or isentropic), the thermal expansion tensor, and the heat capacity at constant strain.