To improve your hyperelastic material model, follow these recommendations:
Note:
Most solid rubber materials have very little compressibility compared to their shear flexibility and are modeled as incompressible in a FEA simulation. This behavior is not a problem with plane stress, shell, or membrane elements. However, it can be a problem when using other elements, such as plane strain, axisymmetric, and three-dimensional solid elements. For example, in applications where the material is not highly confined, it would be quite satisfactory to assume that the material is fully incompressible: the volume of the material cannot change except for thermal expansion.
In cases where the material is highly confined (such as an O-ring used as a seal), the compressibility must be modeled correctly to obtain accurate results. Compressibility is defined as the ratio of the initial bulk modulus to the initial shear modulus . Poisson's ratio, , also provides a measure of compressibility since it is defined as . |