Structural Engineering and Mechanics

Volume 64, Number 5, 2017, pages 527-541

DOI: 10.12989/scs.2017.64.5.527

On the size-dependent behavior of functionally graded micro-beams with porosities

Lemya Hanifi Hachemi Amar, Abdelhakim Kaci and Abdelouahed Tounsi

Abstract

In this work, a new hyperbolic shear deformation beam theory is proposed based on a modified couple stress theory (MCST) to investigate the bending and free vibration responses of functionally graded (FG) micro beam made of porous material. This non-classical micro-beam model introduces the material length scale coefficient which can capture the size influence. The non-classical beam model reduces to the classical beam model when the material length scale coefficient is set to zero. The mechanical material properties of the FG micro-beam are assumed to vary in the thickness direction and are estimated through the classical rule of mixture which is modified to approximate the porous material properties with even and uneven distributions of porosities phases. Effects of several important parameters such as power-law exponents, porosity distributions, porosity volume fractions, the material length scale parameter and slenderness ratios on bending and dynamic responses of FG micro-beams are investigated and discussed in detail. It is concluded that these effects play significant role in the mechanical behavior of porous FG micro-beams.

Key Words

shear deformation theory; bending; vibration; micro beam; porosity; functionally graded material

Address

Lemya Hanifi Hachemi Amar : Faculté de Technologie, Département de Génie Civil et Hydraulique, Université Dr Tahar Moulay, BP 138 Cité En-Nasr 20000 Saida, Algérie; Laboratoire des Ressources Hydriques et Environnement, Université Dr Tahar Moulay, BP 138 Cité En-Nasr 20000 Saida, Algérie Abdelhakim Kaci : Faculté de Technologie, Département de Génie Civil et Hydraulique, Université Dr Tahar Moulay, BP 138 Cité En-Nasr 20000 Saida, Algérie; Material and Hydrology Laboratory, Faculty of Technology, Civil Engineering Department, University of Sidi Bel Abbes, Algeria Abdelouahed Tounsi : Material and Hydrology Laboratory, Faculty of Technology, Civil Engineering Department, University of Sidi Bel Abbes, Algeria; Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Eastern Province, Saudi Arabia; Laboratoire de Modélisation et Simulation Multi-échelle, Département de Physique, Faculté des Sciences Exactes, Département de Physique, Université de Sidi Bel Abbés, Algeria