ABSTRACT
A constitutive equation is a mathematical relation connecting stress and strain for a particular material. Of course, stress and strain are tensorial quantities. Besides stress and strain, some additional quantities, the material constants (e.g. YOUNG'S modulus), appear within a constitutive equation. The values of the material constants adjust the constitutive equation to a particular material, i.e. they make possible to distinguish e.g. between an elastic rubber and an elastic steel.
