Non-Fick mechanical-diffusion with space-dependent diffusivity and time-domain finite element method for transient impact responses analysis

Abstract

The mechanical-diffusion coupling behavior between molar concentration and strain fields have aroused great interest in biosensors, artificial muscles and actuators of adaptive structures and so on. In such nonuniform concentration environment, the space-dependent diffusivity verified in experimental observation is still not considered. Present work aims to establish the non-Fick mechanical-diffusion model with space-dependent diffusivity. To numerically solve the nonlinear governing equations, the time-domain finite element method is developed based on the principle of virtual work. The newly established model and numerical approach are applied to investigate impact responses of a thick circular plate with space-dependent diffusivity under transient chemical shock loadings. With the increase in the space-dependent diffusivity parameter, the dimensionless results reveal that the diffusive wave propagation is proportionally accelerated. And the nonlinear mechanical/chemical responses are maximally enhanced.