in this article, the bending and free vibration analysis of functionally graded (fg) nanocomposites timoshenko beam model reinforced by single-walled boron nitride nanotube (swbnnt) using micro-mechanical approach embedded in an elastic medium is studied. the modified coupled stress (mcst) and nonlocal elasticity theories are developed to take into account the size-dependent effect. the mechani...

The vibration analysis is an important step in the design and optimization of microsensors. In most of the cases, COMSOL software is employed to consider the size-dependency on the dynamic behavior in the MEMS sensors. In this paper, the Modified Couple Stress Theory (MCST) is used to capture the size effect on dynamic behavior in a microsensor with two layers of the silicon and piezoelectric. ...

In this paper, the free vibration behaviors and flexural sensitivity of atomic force microscope cantilevers with small-scale effects are investigated. To study the small-scale effects on natural frequencies and flexural sensitivity, the consistent couple stress theory is applied. In this theory, the couple stress is assumed skew-symmetric. Unlike the classical beam theory, the new model contain...

the problem of several finite moving cracks in a functionally graded material is solved by dislocation technique under the condition of anti-plane deformation. by using the fourier transform the stress fields are obtained for a functionallygraded strip containing a screw dislocation. the stress components reveal the familiar cauchy singularity at thelocation of dislocation. the solution is empl...

The type plant of Allium akaka S.G. Gmelin ex Roem. & Schult. was probably collected in the mountains west of Bandar Anzali. Here plants fitting the original description are extant, and one was selected as epitype. This taxon in the strict sense is not conspecific with A. latifolium Jaub. & Spach, and is morphologically well separable from topo-typical plants of A. haemanthoides Boiss. & Reut. ...

In this study, torsional wave propagation is investigated in a rod that are made of one and two dimensional functionally graded material. Firstly, the governing equations of the wave propagation in the functionally graded cylinder derived in polar coordinate. Secondly, finite difference method is used to discretize the equations. The Von Neumann stability approach is used to obtain the time ste...

Unlike nonlocal models, there is no need to introduce an internal length in the constitutive law for lattice model at the mesoscopic scale. Actually, the internal length is not explicitly introduced but rather governed by the mesostructure characteristics themselves. The influence of the mesostructure on the width of the fracture process zone which is assumed to be correlated to the characteris...

This paper presents a procedure to determine an element-length dependent strain and stress relation until fracture that is suitable for implementation in finite element models. This material relation is obtained experimentally with an optical measuring system. The strain until fracture is calculated from the measured surface displacements. The stress is derived from the measured force and the c...

This study was conducted to investigate the hair production and fleece characteristics of hairy goats according to the sex and age of animals. The material of the study consisted one total data of 73 hair goats, which were between more than one year-old and one year-old Lori goats from both sexes (26 males and 47 females). The overall fleece weight, fiber length, lock length, washing yield, hai...

Short pulsed laser is preferred to avoid the thermal damage in processing the heat sensitive material, such as carbon fiber reinforced plastic (CFRP). In this paper, a numerical model capturing both the material ablation and polymer matrix pyrolysis processes in pulsed laser processing is established. The effect of laser pulse length from ns order to μs order is studied. It was found that with ...