Composite materials with viscoelastic interphase: creep and relaxation

Abstract The effect of viscoelastic interphase between elastic constituents of composites is investigated on the basis of a correspondence principle relating effective elastic and viscoelastic properties of composites, which has been previously established. Previously derived results for thermoelastic properties of unidirectional fiber composites and spherical particle composites with elastic interphase are utilized in this fashion to obtain corresponding viscoelastic effective properties. The analysis shows that significant viscoelastic effect in such unidirectional composites is confined to axial and transverse shear relaxation and creep and in particulate composites to any shear loading. The viscoelastic effect is negligible for all inputs which do not include such shear components.