Moving load excited dynamics of multi-layered imperfect microplates based on various micromechanical models

This paper presents an investigation into the importance of micromechanical models in the analysis of forced vibrations of multi-layered microplates under a moving load. The microplate has a core fabricated from functionally graded materials and face sheets consisting of metal foam. The problem is modelled via a quasi-3D shear deformable method and the modified couple stress theory. This study assumes that the core material follows a power gradation pattern. Various micromechanical models, i.e., the Hashin-Shtrikman bounds, Voigt-Reuss-Hill, Voigt, Reuss, and Tamura, are applied to estimate the material characteristics of the core. The face sheets, composed of metal foams, possess closed- and open-cell solid porosities. System's response of time history type is determined by numerically solving the coupled motion equations obtained using a force-moment balance method. A finite element analysis is conducted for a simplified macroplate system, and the agreement between the numerical results, via the proposed theoretical approach and the theory developed in this paper, is found to be very good. The results show that the micromechanical models influence the modelled mechanical properties of the core layer, consequently impacting the numerical results for the moving-load excited response of the multi-layered microsystem.