Advances in Nano Research

Volume 20, Number 6, 2026, pages 869-898

DOI: 10.12989/anr.2026.20.6.869

Advanced shear deformation theory for bending analysis of porous multidirectional functionally graded nanobeams

Ali Alnujaie , Ahmed A. Daikh , Amin Sami Hamdi , Azza M. Abdraboh , Amr E. Assie , Mohamed A Eltaher , Alaa A. Abdelrhmaan

Abstract

This study presents a comprehensive analytical investigation of the static bending behavior of functionally graded (FG) porous nanobeams incorporating size-dependent effects based on nonlocal strain gradient elasticity theory. A unified quasi-3D formulation with three displacement variables is developed, accounting for thickness stretching and higher-order shear deformation effects. The material properties are assumed to vary smoothly in both axial and transverse directions following power-law distributions, while different porosity patterns (even, uneven I, and uneven II) are considered to capture realistic material degradation. Three grading configurations, namely FG-2D, FG-T, and FG-A, are examined under various loading conditions (sinusoidal, uniform, and linear) and boundary constraints. The governing equations are derived using Hamilton's principle and solved via Galerkin's method. The influence of nonlocal parameter, length-scale parameter, porosity coefficient, and gradation indices on deflection and stress responses is systematically analyzed. The results reveal strong size-dependent behavior, where nonlocal effects tend to soften the structure while strain gradient effects introduce stiffness enhancement. Moreover, porosity significantly increases deflection and stress levels, while FG-A and FG-T configurations exhibit distinct stiffness characteristics compared to FG-2D. The proposed model demonstrates high accuracy, efficiency, and versatility in capturing the mechanical response of porous FG nanobeams.

Key Words

bending; elastic foundation effects; FGM; Galerkin method; porosity distribution; porous nanobeams; Quasi-3D beam model; size-dependent effects

Address

PDF Viewer

Preview is limited to the first 3 pages. Sign in to access the full PDF.

Loading…