A three-fields coupled numerical framework for transient deformation of thermo-sensitive hydrogel

Abstract

As a common smart hydrogel, thermo-sensitive hydrogel exhibits significant potential applications in the field of biological engineering due to its unique property of undergoing a substantial volume transition in response to temperature changes. For numerical implementation of thermo-sensitive hydrogel, many approaches have been developed to simulate the transient deformation during fluid diffusion or heat conduction process. However, the numerical approach for the transient deformation during both fluid diffusion and heat conduction processes is still lacking. To this end, we develop a three-field coupled finite element framework that can be used to simulate the transient deformation behavior of thermo-sensitive hydrogel involving large deformation, fluid diffusion, and heat conduction. In the proposed framework, there exist three processes that deal with displacement, concentration, and temperature fields, separately. To realize the coupling of three fields, the separated solving processes are assembled together by using a two-way coupled approach. Based on the developed finite element framework, the coupling effects between the concentration and temperature can be realized by defining a body flux and a temperature-dependent diffusion coefficient without solving the complex coupling equations. The finite element framework is implemented in ABAQUS by utilizing several user subroutines. The numerical implementation is validated by comparing the numerical results of a hydrogel disk with experimental results. Furthermore, various numerical examples are simulated to investigate the applicability of the proposed finite element framework under different multi-field coupling conditions. The proposed finite element scheme is proved to be an efficient and stable tool for numerically simulating the transient behavior of thermo-sensitive hydrogel incorporating the phase transition effect.