Elastik temel üzerine oturan gözenekli çekirdekli fonksiyonel derecelendirilmiş sandviç kirişlerin statik, dinamik ve stabiliteanalizi

This thesis presents a comprehensive study of static, dynamic, and stability analyses of functionally graded sandwich beams (FGSBs) with porous core resting on a WinklerPasternak elastic foundation. The research focuses on the free vibration, buckling, and bending characteristics of FGSBs with three different core configurations: porous ceramic core, metallic core, and functionally graded (FG) porous core. A power-law distribution is used to model the gradual variation of material properties across the thickness, considering three distinct porosity patterns: uniform, symmetric, and asymmetric. A general theoretical formulation is derived from a quasi-3D deformation theory. The governing equations of motion are obtained using Hamilton's principle and Lagrange's equations. Analytical models, formulated using the Navier and Ritz methods, are complemented by a novel three-node higher-order finite element model. Additionally, a novel FGSB modeling technique is presented using Ansys Mechanical APDL. The accuracy and efficiency of these quasi-3D models are demonstrated and validated through comparisons with existing literature. The study explores the effects of material property homogenization schemes, transverse normal deformation, boundary conditions, structural configurations, porosity characteristics, and foundation parameters on natural frequency, critical buckling, bending, and stress responses. The findings reveal that the introduction of porosity into the core ofFGSBs significantly influences their mechanical behavior, with symmetric porosityconfigurations resulting in superior performance.