Numerical low-velocity impact and structural damping analysis of a rectangular poroelastic plate

Application of porous structures whose voids are naturally or artificially contain fluids is common in several engineering fields such as plates with foams containing humidity or damping fluids, wooden plates subject to humidity, and bones. In the present paper, impact analysis of the poroelastic plates is accomplished for the first time. In this regard, the constitutive equations of the poroelastic materials are proposed based on Biot’s theory and then, the governing equations of the impact of the plate are derived based on the classical plate theory and the non-linear Hertz law. The non-linear finite element form of the governing equations is obtained based on Galerkin method and solved using a special algorithm. Newmark’s numerical time integration method is employed to consider the time-dependency of the resulting equations. Based on the written computer code, effects of various parameters are investigated. Results reveal that presence and flow of the trapped fluid can lead to behaviors that are in contradiction to those of the traditional plates. Furthermore, the contact force, indentation, central deflection of the plate and the bending moment due to the trapped fluid may increase by increasing the diffusion coefficient.