Microstructure effects in wavy-multilayers with viscoelastic phases

Microstructure effects in wavy-multilayers have been an important object of investigation due to several technological applications of this microstructure architecture found in practice, which includes bio-inspired materials. The investigated microstructure consists of stiff elastic wavy layers embedded in substantially softer viscoelastic matrix. The soft matrix does not produce much resistance as the wavy crimp pattern unfolds due to applied transverse loads, producing a stiffening effect, which depends on the local bending stiffness (or moment of inertia) controlled by the layer thickness. This microstructure effect has already been investigated in previous works considering elastic-plastic and non-linear elastic phases, in the infinitesimal and finite deformation domains, respectively. In this work, we further extend this investigation, employing the generalized FVDAM theory for the analysis of periodic materials with viscoelastic phases. As previously documented, this microstructure effect is negligible in the infinitesimal elastic domain, but it is significantly magnified along the time, when the viscoelastic effects take place. Different volume fractions and amplitude-to-wavelength ratios are considered for the analyzed multilayers. The outlined discussion about the results of the conducted investigation becomes clear the importance of that stiffening effect for the design of viscoelastic wavy-multilayers.