Generalized thermoelastic diffusion problems with fractional order strain

Abstract

The studies of the coupling of thermodiffusion and mechanical deformation in solids have aroused great interests with miniaturization of the micro/nano-electromechanical devices and wide application of ultrafast heating technologies. In such situation, it is commonly accompanied with high heat/diffusion flux and thermal/diffusion induced stress accordingly. So far, although there have been many developments and extensions of research and theorizing within the generalized thermoelastic diffusion problems, these theoretical formulations are only applicable when the strain rate is assumed to be relatively small, but this is questionable under ultrafast heating condition. The present work aims to investigate generalized thermoelastic diffusion problems with fractional order strain within the extended thermodynamic framework. For numerical evaluation, the analytical model of a sandwich structure with ideal interfacial conditions is investigated whilst its bounding surfaces are subjected to symmetrical transient heat and chemical potential shock loads. From numerical results, the effects of the fractional order parameters and material characteristic parameters of each layer on structural transient thermo-elasto-diffusive responses are also analyzed and discussed, which is expected to provide a comprehensive understanding on thermoelastic diffusive coupling and optimal design of sandwich structures under extreme fast heating condition.