Elastic moduli and Poisson ratio for amorphous polymers and glasses

We propose that the product of the density by the square of the rms velocity of strain waves, which exhibits the features typical of elastic moduli, be referred to as effective (or characteristic) elastic modulus. The ratio of the bulk compression modulus to the effective elastic modulus is a single-valued function of the Poisson ratio not only for crystals and glasses, but also for amorphous organic polymers. The effective elastic modulus may be helpful in analysis of anharmonism of lattice vibrations of deformable bodies.