Bending and vibration analysis of three-phase bi-directional functionally graded porous sandwich plates

This study presents a semi-analytical approach for analyzing the bending and free vibration behavior of three-phase bi-directional functionally graded porous sandwich plates (2D-FGPSW). The sandwich plates considered feature face sheets with biaxial material gradation composed of three distinct constituents and a thickness-varying functionally graded porous core. Such structural configurations are relevant to advanced engineering applications requiring high strength-to-weight ratios and tailored mechanical performance. The analysis is based on Reddy’s third-order shear deformation theory and employs the pb2-Ritz method to obtain accurate solutions under various boundary conditions, with convergence checked through appropriate term selection. The model is validated through comparison with available benchmark solutions. A comprehensive parametric study is conducted to evaluate the effects of material gradation, geometric parameters, sandwich configurations, and boundary conditions on the structural response. The results contribute to a deeper understanding of the mechanical behavior of complex sandwich structures and support the design of efficient and lightweight composite systems.