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Open access

Rajneesh Kumar, Shaloo Devi and Veena Sharma

Abstract

This paper deals with the study of thermoelastic thin beam in a modified couple stress with three-phase-lag thermoelastic diffusion model subjected to thermal and chemical potential sources. The governing equations are derived by using the Euler-Bernoulli beam assumption and eigenvalue approach. The Laplace transform technique is employed to obtain the expressions for displacements, lateral deflection, temperature change, axial stress and chemical potential. A particular type of instantaneous and distributed sources is taken to show the utility of the approach. The general algorithm of the inverse Laplace transform is developed to compute the results numerically. The numerical results are depicted graphically to show the effects of phase lags, with and without energy dissipation on the resulting quantities. Some special cases are given.

Open access

P. Muthu

Abstract

Resistance spot welding (RSW) is a fabrication process that is being used in the automobile and aerospace industry since many years for joining low carbon or “mild” steel. Quality and strength of the welds depend upon the process parameters of RSW. The most effective parameters in this process are: current intensity, welding time, sheet thickness and material, geometry of electrodes, electrode force, and current shunting. This paper presents the experimental investigations for the optimization of tensile shear stress of RSW for stainless steel grade 316L sheets by using Taguchi method. The experiments were conducted using Taguchi’s L27 orthogonal array under varying process parameters, namely electrode diameter, welding current, and heating time. The experimental data were analyzed using signal-to-noise ratio (S/N ratio) to find the optimal process parameters. Analysis of variance (ANOVA) and F test were used to find the most significant parameters affecting the spot weld quality characteristics. Confirmation tests with optimal process parameters were conducted to validate the test results. From the results, it was found that it is possible to increase tensile shear stress significantly.

Open access

Prashant Elango and K. Prakash Marimuthu

Abstract

Drilling is a cutting process that uses a drill bit to cut a circular profile in workpiece. Forces acting on the drill bit reduce its life expectance. Analysis of forces acting on the drill bit during drilling prevents the tool from failing prematurely because of wear and excess feed rate. Excess feed rate can induce excessive internal stress on both the tool and workpiece. This paper aims to study the effects of reaction force acting on a drill bit during drilling of Al6061-T6. A numerical finite element simulation study is performed with commercially available software called Abaqus. Simulation results depend on the right choice of material property such as Johnson–Cook material property and Johnson–Cook damage property. Validation of material property is achieved by comparison of experimental results with simulative results. Reaction force acting against the drill bit during drilling is compared.

Open access

R. Bouchenafa, Hussein A. Mohammed and R. Saim

Abstract

The aim of this paper is to numerically investigate the thermal and hydraulic performances of the two heat sinks made of wavy fins (WFHS). The governing equations fitted with boundary conditions were solved using the finite volume method, and the SIMPLE algorithm for the coupling velocity-pressure. The two-equation model k-ϵ was used to describe the turbulence phenomenon. The effects of wave numbers and the amplitude of wavy fins heat sink on the thermal and flow fields are studied and compared with the plate fin heat sink (PFHS). The results show that the use of wavy fins improves significantly the heat transfer rate, accompanied by a pressure drop penalty.

Open access

Sid Ahmed Reffas, Mohamed Benguidiab, Ondrej Sikula, Houari Adjlout and Habib Lebbal

Abstract

The objective of this work is the analysis of the fracture behavior of a SENB cylinder with a defect where stress triaxiality is more severe. Numerical simulations are carried out in a 2D mode, to overcome a disadvantageous hypothesis plane strain or plane stress. The mesh sensitivity studies were also undertaken but are not presented here. Indeed, only the results for the most relevant mesh are the subject of the discussion.

Open access

Djelaili Abdelbaki and Korti Abdel Ilah Nabil

Abstract

Building designers have to think about new strategies to achieve the best sustainable building designs. Well-planned passive solar heating strategies in building design may reduce a building’s energy consumption significantly. In this paper, a proposed design of the south façade of a room by integrating a hybrid solar wall and a window to passively heat a room is studied. The simulations for the three-dimensional model of BIPV Trombe wall system were carried out for December 10th, 2015. The temperature and velocity distribution of indoor air in different positions inside the room are obtained from the simulation results. The obtained results show that the temperature difference between the inlet and the outlet of the solar wall can reach 9°C. The 3D analysis of the proposed model clearly shows that the window’s thermal effect on the passive heating cannot be neglected. Meanwhile, the simulation’s daily electrical efficiency conversion and average indoor air temperature of this system can reach 18% and 28° C, respectively for maximum solar radiation of 470 W/m2.

Open access

Krzysztof Kurc, Andrzej Burghardt, Dariusz Szybicki and Józef Giergiel

Abstract

This article presents the process of designing a robot with a magnetic pressure pad for inspections of ferromagnetic ventilation ducts. In compliance with the assumptions, the CAD design of the robot was developed in a 3D programming environment. The designing process brought about a mathematical model of the robot with one pair of magnetic drive modules, including simulation in a MATLAB/Simulink environment. The model accounted for parameters such as rolling resistance force, transverse resistance moment, magnetic attraction force, solid moment of inertia, and other factors. The magnetic pressure pad allowed for moving the robot in magnetic ventilation systems irrespective of slopes and shapes of ducts.

Open access

Puja Basu Chaudhuri, Anirban Mitra and Sarmila Sahoo

Abstract

This article deals with finite element method for the analysis of antisymmetric angle-ply laminated composite hypar shells (hyperbolic paraboloid bounded by straight edges) that applies an eight-noded isoparametric shell element and a three-noded beam element to study the mode-frequency analysis of stiffened shell with cutout. Two-, 4-, and 10-layered antisymmetric angle-ply laminations with different lamination angles are considered. Among these, 10-layer antisymmetric angle-ply shells are considered for elaborate study. The shells have different boundary conditions along its four edges. The formulation is based on the first-order shear deformation theory. The reduced method of eigen value solution is chosen for the undamped free vibration analysis. The first five modes of natural frequency are presented. The numerical studies are conducted to determine the effects of width-to-thickness ratio (b/h), degree of orthotropy (E 11/E 22), and fiber orientation angle (θ) on the nondimensional natural frequency. The results reveal that free vibration behavior mainly depends on the number of boundary constraints rather than other parametric variations such as change in fiber orientation angle and increase in degree of orthotropy and width-to-thickness ratio.

Open access

Arvind Kumar, S. M. Abo-Dahab and Praveen Ailawalia

Abstract

This paper is concerned with the study of propagation of Rayleigh waves in a homogeneous isotropic piezo-electric microstretch-thermoelastic solid half-space. The medium is subjected to stress-free, isothermal boundary. After developing a mathematical model, the dispersion curve in the form of polynomial equation is obtained. Phase velocity and attenuation coefficient of the Rayleigh wave are computed numerically. The numerically simulated results are depicted graphically. Some special cases have also been derived from the present investigation.

Open access

Dominik Banat

Abstract

The subject of this article is the finite element method (FEM) simulation of the multi-layered rectangular composite beam subjected to three-point bending test. The study is focused on the composite beams made of glass or carbon fibre-reinforced laminates (glass fibre-reinforced polymer [GFRP] and carbon fibre-reinforced polymer [CFRP]) for which different laminate stacking were addressed. Three beam geometries with various length-to-thickness ratios included short beam shear (SBS) test, provided the beam is short relative to its thickness, which maximised the induced shear stresses. Simulation included the application of Tsai–Hill, Hoffman, Tsai–Wu, Hashin and Puck failure criteria to perform the composite beam failure analysis wherein the matrix and fibre failure were considered separately. Numerical failure studies also aimed to verify the beam failure modes and the participation of stress tensor elements in material failure.