Earthquakes and Structures

Volume 29, Number 5, 2025, pages 353-369

DOI: 10.12989/eas.2025.29.5.353

Free vibration of new model of FG beams using state space approach

Radim Ghelamallah, Tlidji Youcef, Benferhat Rabia and Hassaine Daouadji Tahar

Abstract

This work aims to study the natural frequencies of functionally graded beams by applying the higher-order shear deformation theory (HDT). The study focuses on the variation of mechanical properties across the beam's thickness. A new model of FGM beams is proposed, in which the material properties are governed by a novel power-law distribution of the volume fraction, varying from the exterior to the interior of the beam. By applying Hamilton's principle, the governing equations are derived using the state-space method. The accuracy of this method is demonstrated for the classical beam model, and the obtained results are validated through comparisons with previous studies. A comprehensive analysis is carried out to evaluate the impact of key parameters, such as the power-law index and the slenderness ratio, on the natural frequencies of functionally graded beams under various boundary conditions.

Key Words

boundary conditions; HDT; natural frequencies; new model of FG beam; state space method

Address

Radim Ghelamallah and Tlidji Youcef: 1) Department of Civil Engineering, University of Tiaret, Algeria, 2) Materials and Structures Laboratory, Civil Engineering Department, University of Tiaret, Algeria Benferhat Rabia and Hassaine Daouadji Tahar: 1) Department of Civil Engineering, University of Tiaret, Algeria, 2) Laboratory of Geomatics and Sustainable Development, University of Tiaret, Algeria