Volume 11 Issue 2


Investigation of the free vibrational behavior of carbon nanotube-reinforced composite beams

Amira Khaldi, Sabiha Tekili, Khadri Youcef

Abstract: This study investigates the free vibration behavior of nanocomposite beams reinforced with agglomerated single-walled carbon nanotubes (SWCNTs) embedded in an epoxy matrix. The effective material properties of the reinforced composite are estimated using the Weng model, and the equation of motion for the beam is derived based on Euler-Bernoulli beam theory. A MATLAB code is developed to determine the natural frequencies and eigenmodes of the nanocomposite beams. The results demonstrate that the elastic modulus of the agglomerated CNT composite increases with the increasing volume fraction of CNTs, leading to an increase in natural frequencies.

Keywords: Free Vibration, Beam, Carbon, Nanotubes, Composite, Single-Walled.


Effect of material tools and cutting conditions on surface roughness during the turning of Ti-6Al-4V alloy: statistical analysis and modeling

Khaoula Abbed, Nabil Kribes, Mohamed Athman Yallese, Smail Boutabba, Younes Belbellaa

Abstract: Given its exceptional physical and mechanical properties, Ti-6Al-4V is often considered one of the more challenging titanium alloys to machine, notorious for damaging cutting tools due to its aggressiveness. The aim of this current research is to evaluate the effects of cutting conditions (CS, Doc, and FR), as well as coated (TiN and TiAlN), and uncoated cutting carbides (H13A) on response parameters during the dry machining of the Ti-6Al-4V alloy. Using the ANOVA approache, a set of experiments based on Taguchi L9 were done to find out how different input parameters affected the roughness of the surface. The results, obtained through statistical treatment employing the RSM methodology, facilitated the development of predictive mathematical models for each of the cutting tools. The numerous well-founded results acquired are of interest to mechanical manufacturing companies and academic researchers involved in Ti-6Al-4V studies.

Keywords: Ti-6Al-4V, Turning, ANOVA, Modeling, RSM, Surface roughness, H13A, TiAlN, TiN


Strong coupling fluid–structure interactions of a turbine impeller in a stirred vessel

Sarhan Karray, Zied Driss, Hedi Kchaou, Mohamed Salah Abid

Abstract: In this paper, a coupling algorithm is developed in a partitioned approach using strong scheme to provide the time history of the fluid flow and structure parameters. These parameters affect the unsteady behaviour of the turbine since the blades are flexible. Exploring the repressed area of the turbine, this allows to follow the passing of the baffle front of the turbine blades and the deformation of the blade, in particular. The fluid flow is governed by the Navier–Stokes equations for incompressible viscous fluids and modelled with the finite volume method. The structure is represented by a finite element formulation. The control of the history time of the fluid flow and structure parameters, such as the three components of velocity, turbulent kinetic energy, its dissipation rate and the blade displacement enables to understand the mass transfer phenomenon. This will show the effect of the interaction between the various components of the geometry system. Predictions of the numerical results have been compared to the literature data, and a satisfactory agreement has been found.

Key words: Computational Fluid Dynamics (CFD), Computational structure Dynamics (CSD), fluid-structure interaction (FSI), Strong coupling algorithm, Turbine.

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