Generalized Stress-Strain Hookes Law for Isotropic Solids

7 GENERALIZED STRESS-STRAIN HOOKE S LAW FOR ISOTROPIC SOLIDS 

The components of the modulus tensor Cy have traditionally been expressed in terms of the Lame constants X and G. Specifically, 

Then the relation between the stress and strain tensors is given by the classical expression 

Then the ratio between the volume of the deformed body (V) and that of the undeformed one (Fq) can be written as 

Obviously, A represents the dilatation (or contraction) undergone by an isotropic body because of the action of an external force. It is convenient 

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