Unified numerical analysis for thermoelastic diffusion and thermo-poroelasticity of thin plates

In this paper, we investigate a coupled hyperbolic-parabolic system modeling thermoelastic diffusion (respectively, thermo-poroelasticity) in plates, consisting of a fourth-order hyperbolic partial differential equation for plate deflection and two second-order parabolic partial differential equations for the first moments of temperature and chemical potential (respectively, pore pressure). The unique solvability of the system is established by means of a Galerkin approach, and the additional regularity of the solution is obtained under appropriately strengthened data. For numerical approximation, we employ the Newmark method for time discretization of the hyperbolic term and a continuous interior penalty scheme for the spatial discretization of displacement. For the parabolic equations that represent the first moments of temperature and chemical potential (respectively, pore pressure), we use the Crank–Nicolson method for time discretization and conforming finite elements for spatial discretization. The convergence of the fully discrete scheme with quasi-optimal rates in space and time is established. The numerical experiments demonstrate the effectiveness of the 2D Kirchhoff–Love plate model in capturing thermoelastic diffusion and thermo-poroelastic behavior in specific materials. We illustrate that, as plate thickness decreases, the two-dimensional simulations closely approximate the results of the three-dimensional problem. Finally, the numerical experiments also validate the theoretical rates of convergence.