Incompressible and Linearly Compressible Viscoelastic Creep and Relaxation

Abstract

It is shown that defining an incompressible material as one whose response to stressing or straining is insensitive to volumetric-type changes in strain or stress allows the derivation of incompressible forms for multiple integral representations, through the third order, which have only three kernel functions both in the creep formulation and the relaxation formulation for small strains. Earlier work had yielded four kernel functions in the relaxation and three in the creep formulation. Linearly compressible formulations are also discussed and compared with available creep data.