Glossary

Hyperelasticity

Theoretical framework for modeling the nonlinear elastic response of materials. It is based on the postulate of the existence of a strain energy density function. Stresses are then defined by the derivative of this energy with respect to strains.

Strain energy density

Scalar function dependent on a measure of deformation. It is defined per unit of undeformed volume and must verify a number of mathematical properties to be physically valid. Depending on the characteristics of the material (amplitude of deformation, isotropy or not, compressibility or not, etc.), its expression is more or less complex. Once the form of this energy has been chosen, the stress-strain relationship is fully defined.

Incompressibility

Restriction on the movements a body can...