A Moore-Gibson-Thompson Thermoelastic Model for Spatio-Temporal Nonlocalized Porous Hollow Cylinders with Memory-Dependent Heat Conduction

A generalized thermoelastic model has been developed for porous media by combining Moore-Gibson-Thompson (MGT) thermoelasticity with spatio-temporal nonlocality and memory-dependent heat conduction. The porous skeleton is described within a thermoelastic framework enriched by a Klein-Gordon-type operator in the constitutive relations to capture nonlocal interactions in space and time, while a memory-dependent derivative (MDD) is incorporated into the MGT heat conduction equation to represent finite-speed, history-dependent thermal transport. The resulting model is applied to a hollow, porous cylinder subjected to thermal shock. The coupled field equations for displacement, temperature, and volume fraction are formulated and solved in the Laplace domain, and the physical fields in the time domain are obtained by numerical inversion of the Laplace transforms. A series of parametric studies have been conducted with the objective of elucidating the roles of the time-delay factor, the kernel function, nonlocal parameters and porosity-related coefficients on the distributions of thermoelastic fields. The variations in the void volume fraction demonstrate the significant impact of spatio-temporal nonlocal effects on the interaction between local deformation and neighbouring regions in porous materials. In addition, transient responses predicted by the proposed model are systematically compared with those from classical thermoelastic theories that neglect memory and nonlocality. The findings demonstrate that incorporating MDD-based heat conduction and nonlocal effects results in significant alterations to the transient behaviour, thereby facilitating a more precise and accurate depiction of the dynamic response of porous thermoelastic structures.