Electro-Elasto-Statics of porosity-gradient smart functionally graded plates with piezoelectric fibre-reinforced composite

Smart structures offer functional advantages over conventional composites through capabilities of material tailoring and controlled response under external actuation/sensing. The porosity induced in functionally graded (FG) materials due to manufacturing processes can be detrimental to the strength and durability characteristic of aerospace/automobile components. On the other hand, porosities act favourably for biomedical implants with blood circulation functionality in connecting tissues and stress shielding effect with compatibility between the natural and implant components. To accurately model smart porous FG structures under electrical and mechanical loads, a polynomial-based higher order shear and normal deformation theory (HOSNT) is utilized for the first time in this work. The governing equations are derived using the variational energy principle, and analytical solutions are obtained using Navier's solution method. The transverse shear stresses are obtained using a one-step stress recovery process. The influence of various porosity distribution models is studied on the bending response of smart porous FG plates. The effect of actuation voltage, porosity coefficient, material gradation index are critically assessed, and benchmark solutions for the class of problems are proposed. It is observed that stress response through thickness doesn't change monotonically with the change in porosity coefficient; instead, regions of higher and lower stresses are obtained with respect to the non-porous plate. Voltage-actuated FG plates are shown to have a steeper fall in stresses away from the piezo-layer compared to the conventional composites.