THEORY OF ELASTICITY FOR AN ISOTROPIC BODY WITH DIFFERENT MODULI IN TENSION AND COMPRESSION.

There are many materials that have different moduli in tension and compression. The properties of such dimodular materials can be described with the aid of a potential that depends on the first and second invariants of the stress tensor. The potential for the classical elastic body is a special case of this. A method for determining the functions and the constants in the expression for the potential is described. Possible forms of the stress-strain diagrams under proportional and nonproportional loading are discussed. Finally, the validity of certain theorems of the theory of elasticity in the case of dimodular materials is analyzed.