Isotropic Material

This material is a small strain, linear elastic material. The components stress are related to components of strain by

[math]\displaystyle{ \sigma_{ij} = \bigl(\lambda\varepsilon_{ii} - 3K(\alpha \Delta T+\beta c)\bigr)\delta_{ij} + 2G\varepsilon_{ij} }[/math]

where λ is the Lame, K is bulk modulus, α is thermal expansion coefficient, ΔT is temperature difference, β is solvent expansion coefficient, c is solvent concentration, and G is shear modulus. Two other isotropic material properties are modulus, E, and Poisson's ratio, ν.

Although an isotropic material can be defined any two of λ, K, G, E, and ν, the only properties allowed for defining this material are E and ν.