rss_2.0International Journal of Applied Mechanics and Engineering FeedSciendo RSS Feed for International Journal of Applied Mechanics and Engineering Journal of Applied Mechanics and Engineering Feed of Form Defect on the Mechanical Behavior and Stress Intensity Factor of Shrink-Fitted Thick-Walled Cylinders<abstract> <title style='display:none'>Abstract</title> <p>In this research work, the finite element software, ABAQUS is used to study by simulations the influence of form defect on mechanical behavior of a shrink-fitted assembly presenting internal radial cracks. Under the action of contact pressure induced by the tightening between two cylinders, these cracks resulting from incorrect assembly operations or materials elaboration defect, can be harmful to the assembly. Various simulations were carried out in two modeling cases, taking into account the geometric parameters of defect (amplitude Df), of cylinders (thickness t) and of cracks (length a, ratio a/t). Another important parameter such as the tightening was also considered in the modeling. The first modeling relates to the case with defect, external cylinder presents an oval (elliptical) form defect and internal radial cracks. The other concerns the perfect equivalent case (without form defect). The comparison of results obtained by two models shows that form defect modifies the uniformity of equivalent stresses distribution in cylinders and increases the value of stress intensity factor (SIF) KI in cracks. Defect amplitude and tightening significantly influence the value of equivalent stress and that of stress intensity factor (SIF) <italic>K<sub>I</sub></italic>.</p> </abstract>ARTICLEtrue Approach to Solving a Layered Behaviour Differential Equation with Large Delay Using Quadrature Scheme<abstract> <title style='display:none'>Abstract</title> <p>This paper deals with the computational approach to solving the singularly perturbed differential equation with a large delay in the differentiated term using the two-point Gaussian quadrature. If the delay is bigger than the perturbed parameter, the layer behaviour of the solution is destroyed, and the solution becomes oscillatory. With the help of a special type mesh, a numerical scheme consisting of a fitting parameter is developed to minimize the error and to control the layer structure in the solution. The scheme is studied for convergence. Compared with other methods in the literature, the maximum defects in the approach are tabularized to validate the competency of the numerical approach. In the suggested technique, we additionally focused on the effect of a large delay on the layer structure or oscillatory behaviour of the solutions using a special form of mesh with and without a fitting parameter. The effect of the fitting parameter is demonstrated in graphs to show its impact on the layer of the solution.</p> </abstract>ARTICLEtrue of a High Wear Resistance AA7075/AL2O3 Composites Via Liquid Metallurgy Process<abstract> <title style='display:none'>Abstract</title> <p>In the present study, AA7075/Al2O3 composites have been fabricated via liquid metallurgy process. AA7075 alloy and Al2O3 particles were taken as the base matrix and reinforcements, respectively. Then, contents of 3 and 6 wt. % of Al2O3 subdivisions were added into the AA7075 matrix. To improve wettability and distribution, reinforcement particles were pre-heated to a temperature of <italic>550°C</italic> for each composite sample. A hardened EN32 steel disc as the counter face was used to evaluate the wear rate pin-on-disc. The results showed that the wear rate of the AA/Al2O3 composites was smaller than that of the monolithic AA7075 samples. Finally, the worn surfaces of samples were investigated by SEM.</p> </abstract>ARTICLEtrue Method for Comparison of Large Deflection in Beams<abstract> <title style='display:none'>Abstract</title> <p>The deflection analysis of beams has been recently an active area of research. The large deflection of beams refers to deflections occurring due to large displacements and small strains. This type of deflection has been one of the areas of interest in the development of beam deformation methods. The wide diversity of beam deformation methods highlights the importance of their comparison to further elucidate the properties and features of each method and determine their benefits and limitations. In this study, a new comparison model is introduced which involves three steps, instead of only comparing final results for verification in common studies. In the first step, a complete comparison is made based on the assumptions and approximations of each method of the kinematics of deformation, displacement, and strain fields. After selecting the most accurate method in the first step, the displacement functions are determined by polynomial approximation under different loading and support conditions based on the selected method. In the third step, the displacement functions are used to calculate the strains in each method. The conclusion is based on comparing the strains. This comparative model can be used as a benchmark to compare different theories of deformation analysis.</p> </abstract>ARTICLEtrue Transfer Effects on Carbon Nanotubes Along a Moving Flat Plate Subjected to Uniform Heat Flux<abstract> <title style='display:none'>Abstract</title> <p>In the present paper, a theoretical analysis is made to investigate fluid flow and heat energy transformation features of single and multi-walled water functionalized carbon nanotubes (CNTs) with uniform heat inconstancy boundary conditions onward a flat plate. The liquid motion and momentum transfer of carbon nanotubes (CNTs) have been analyzed using a homogeneous flow model. Both single-wall CNTs (SWCNTs) and multi-wall CNTs (MWCNTs) used base fluids, namely, water. The thermophysical characteristics of CNTs regarding the solid volume fraction of CNTs are studied by applying empirical correlations. Similarity transformations have been used to the governing partial differential equations turning them into ordinary differential equations. The outcome of similarity transformations which are nonlinear ordinary differential equations subjected to reconstructed boundary conditions, are subsequently solved numerically using bvp4c. The effects of the governing parameters on the dimensionless velocity, temperature, and skin friction are investigated numerically and graphically. An increase in the volume fraction and the velocity ratio parameter increase the flow, the velocity, and the temperature profile. Regardless of any physical parameter, SWCNTs give better heat transfer than MWCNTs.</p> </abstract>ARTICLEtrue Plane Waves in a Rotating Thermoelastic Double Porous Solid<abstract> <title style='display:none'>Abstract</title> <p>The propagation of plane waves in a rotating homogeneous, isotropic, thermoelastic solid with double porosity following Lord-Shulman’s theory of thermoelasticity has been investigated. It is assumed that the medium rotates about an axis normal to the surface with a uniform angular velocity. There may exist five coupled waves that evolved due to the longitudinal, transverse disturbance, voids of type-I and type-II, and temperature change in the medium. The secular equation for the model under consideration has been derived with the help of formal solutions and boundary conditions. The amplitude of displacements, temperature change and volume fraction fields for voids of type-I and type-II have also been computed analytically. Finally, numerical computations have been carried out for magnesium crystal material to understand the behavior of amplitude of phase velocity, penetration depth, specific loss, displacement components, temperature change, and volume fraction field due to type-I and type-II voids corresponding to the different rotation rates. Various graphs have been plotted to support the analytical findings. The study may be used in the development of rotation sensors, material design and thermal efficiency.</p> </abstract>ARTICLEtrue Analysis of Functionally Graded Thermoelastic Microelongated Solid<abstract> <title style='display:none'>Abstract</title> <p>The present research focuses on two-dimensional deformation in a functionally graded thermoelastic micro-elongated medium. It is supposed that the non-homogeneous properties (thermal and mechanical) of FGM are in the x-direction. The normal mode technique is used to acquire the analytic expression for displacement components, stress, micro-elongation and temperature. The cause and effect relationship of non-homogeneity and physical quantities is shown through graphical results.</p> </abstract>ARTICLEtrue Number Effects on Dynamic Boundary Layer Evolution Over a Wedge Surface from Initial Flow to Steady Flow: Analytical Approach<abstract> <title style='display:none'>Abstract</title> <p>The present work studies the effects of the physical parameter characterizing the laminar flow regime, namely the Strouhal number, on the evolution of the unsteady dynamic boundary-layer developed along a wedge surface. Similarity method is used to transform unsteady momentum equation to dimensionless form. Using superposition method between diffusion and convective flows solutions, an ad hoc velocity profile formula is proposed. The obtained results confirm perfectly the numerical data given by Blasius, Falkner-Skan and Williams-Rhyne for all Strouhal numbers. A new accurate analytical function of the local skin friction is established for all time values and for different wedge surface directions. In order to give further clarification on the flows evolutions from diffusion flow to convective flow, in the whole space domain, new skin friction coefficient curves are plotted for all Strouhal numbers and for different wedge surface directions.</p> </abstract>ARTICLEtrue Fluid Model in an Inclined Porous Stenosed Artery with Slip Effect and Body Acceleration<abstract> <title style='display:none'>Abstract</title> <p>The present paper analyzes an unsteady magnetohydrodynamic blood flow model of an visco-elastic fluid through an inclined porous stenosed artery with body acceleration and slip effect. Navier-Stokes equations have been used to describe the blood flow model. The governing equation of blood flow is solved by an analytic method by considering blood as an incompressible, visco-elastic fluid, and suspension of RBC’s in plasma. Axial velocity, blood acceleration, flow rate, and shear stress are derived numerically by using the finite Laplace and Hankel transformation and their inverse. The effect of parameters such as the visco-elasticity parameter, Womersley number, Hartmann number, inclination angle, parameter of slip, and body acceleration frequency is analyzed. Axial velocity reduces as the Hartmann number and visco-elasticity parameter enhance and it enhances with the enhancement of the slip parameter and inclination angle. The study is beneficial for finding the effect of slip parameter, porosity factor and Hartmann number when a human body is exposed to MRI and CT scan.</p> </abstract>ARTICLEtrue Influence of Thermal Expansion on Flow Past an Inclined Accelerated Sectional Plate with Persistent Mass Diffusion<abstract> <title style='display:none'>Abstract</title> <p>In this article, we examined the solution of a homogeneously intensified isothermal inclined infinite plate with constant temperature. The plate is elevated to <italic>T<sub>w</sub></italic>, and the species accumulation is enhanced at a consistent speed. Under appropriate boundary conditions, the non-dimensional guiding formulae are remedied using the Laplace transform procedure. The effect of velocity, temperature, and concentration on various factors, including thermal and mass Grashof numbers, Schmidt numbers, and duration, is discussed. The velocity increases proportionally to the thermal and mass Grashof numbers, but decreases as the inclined angle, Schmidt numbers and time increase.</p> </abstract>ARTICLEtrue of Friction Stir Processing Parameters of Aluminum Alloy Reinforced with Hybrid Nanoparticles Using the Taguchi Method<abstract> <title style='display:none'>Abstract</title> <p>This study deals with the selection of optimum parameters for friction stir processing of Al alloy 6061-T6 reinforced with a hybrid nanoparticle (B4C and SiO2) in terms of their effect on the mechanical properties (hardness, tensile strength, and wear resistance) using Taguchi method. This work was carried out under four parameters each one running in three levels; rotational speeds (<italic>800</italic>, <italic>1000</italic> and <italic>1200</italic>) rpm, travel speeds (<italic>10</italic>, <italic>20</italic>, and <italic>30</italic>) mm/min, holes depth (<italic>2</italic>, <italic>2.5</italic>, and <italic>3</italic>) <italic>mm</italic>, and mixing ratio of (SiO2/B4C) nanoparticles (<italic>1/1</italic>, <italic>1/2</italic>, and <italic>1/3</italic>), using <italic>L9</italic> (<italic>34</italic>) Taguchi orthogonal array. Tensile strength and microhardness tests were conducted to evaluate the mechanical properties, in addition to the wear resistance test which is carried out using a pin-on-disk device. The microstructure was examined by optical microscopy, field emission scanning electron microscopy, and x-ray diffraction analysis. It was found that the highest tensile strength (<italic>223</italic>) <italic>MPa</italic> at <italic>1200 rpm</italic> rotational speed, <italic>30 mm/min</italic> traverse speed, <italic>2.5 mm</italic> holes depth, and <italic>1/2</italic> (SiO2/B4C) nanoparticles mixing ratio, the highest hardness reached is (<italic>155</italic>) HV, then decreases in the direction of thermomechanically affected zone (TMAZ), heat affected zone (HAZ), and the base material at (<italic>1200</italic>) <italic>rpm</italic> rotational speed, (<italic>30</italic>) mm/min linear speed, a hole depth of (<italic>2</italic>) mm and (<italic>1/3</italic>) mixing ratio of (B4C/SiO2) nanoparticles. The wear behavior was of a mild type or an oxidative type at low loads (<italic>5 N</italic>), which became severe or metallic wear at higher loads (<italic>20 N</italic>) at fixed sliding time and speed. The (ANOVA) table has been used to determine which parameter is the most significant using MINITAB software.</p> </abstract>ARTICLEtrue Investigation of the Suspension Characteristics of the Line Model of the Vehicle Using the Taguchi Method<abstract> <title style='display:none'>Abstract</title> <p>It can be considered that the suspension system is one of the most important systems in the VEHICLE. Where it is responsible for the stability and balance of the vehicle’s structure on the roads and curves to ensure the comfort of passengers. Also, it absorbs the shocks resulting from the unevenness of the road and prevents it from reaching the wheelhouse. The influence of the suspension constructive parameters in order to obtain the smallest level of displacements of the sprung mass has been investigated. The following control parameters are the stiffness of the sprung, unsprung mass, and the damping of the sprung mass. The parameter which affects most displacements of the sprung mass was determined by applying the analysis of variance (ANOVA). The investigation was conducted using MATLAB/SIMULINK software, and a line model of a quarter of the vehicle was created. It was determined that the stiffness of sprung has the most significant influence on the displacement of the sprung-mass, which further affect the vehicle’s comfort.</p> </abstract>ARTICLEtrue of Ultrasonic Peening on Mechanical Properties of Low Carbon Steel AISI 1020 TIG Welding Joints Process<abstract> <title style='display:none'>Abstract</title> <p>In this paper, the effect of ultrasonic peening surface treatment on the mechanical properties of TIG butt weld joints of low-carbon steel (AISI 1020) was studied. A single V-angle (<italic>45</italic>°) was made on sheets of metal used then welded at constant parameters, namely: current, voltage. Wire filler ER70S-3 with argon was used to obtain many butt welding joints. Some of them were subjected to ultrasonic peening at one, two and three passes. The micro-hardness, microstructure, tensile and bending were tested. The results show increases in the tensile strength after the welding process. The test results showed improvements in the tensile strength of the weldments in comparison to the base metal. On the other hand, the tensile strength decreased with the ultrasonic process. Nevertheless, the tensile strength increased at a high number of ultrasonic passes. On the contrary, the ultrasonic process enhanced the bending strength compared to the base metal, whereas the weldments ability to bend deteriorated.</p> </abstract>ARTICLEtrue Optimization Techniques on Cold-Formed C-Channel Section Under Bending<abstract> <title style='display:none'>Abstract</title> <p>There are no standard dimensions or shapes for cold-formed sections (CFS), making it difficult for a designer to choose the optimal section dimensions in order to obtain the most cost-effective section. A great number of researchers have utilized various optimization strategies in order to obtain the optimal section dimensions. Multi-objective optimization of CFS C-channel beams using a non-dominated sorting genetic algorithm II was performed using a Microsoft Excel macro to determine the optimal cross-section dimensions. The beam was optimized according to its flexural capacity and cross-sectional area. The flexural capacity was computed utilizing the effective width method (EWM) in accordance with the Egyptian code. The constraints were selected so that the optimal dimensions derived from optimization would be production and construction-friendly. A Pareto optimal solution was obtained for 91 sections. The Pareto curve demonstrates that the solution possesses both diversity and convergence in the objective space. The solution demonstrates that there is no optimal solution between 1 and 1.5 millimeters in thickness. The solutions were validated by conducting a comprehensive parametric analysis of the change in section dimensions and the corresponding local buckling capacity. In addition, performing a single-objective optimization based on section flexural capacity at various thicknesses The parametric analysis and single optimization indicate that increasing the dimensions of the elements, excluding the lip depth, will increase the section’s carrying capacity. However, this increase will depend on the coil’s wall thickness. The increase is more rapid in thicker coils than in thinner ones.</p> </abstract>ARTICLEtrue of Carbon Steel AISI 1006 to Aluminum Alloy AA6061-T6 Via Friction Spot Joining Technique<abstract> <title style='display:none'>Abstract</title> <p>This work aims to join sheets of carbon steel to aluminum alloy AA6061. A lap joint arrangement was used with a joint lap area of dimensions * <italic>25 25 mm</italic>. The joining procedure was carried out using a rotating tool of 10 mm shoulder diameter. Three process parameters, with three levels for each parameter, were selected to investigate their effects on joints quality. The parameter’s levels for each experiment were designed using the design of the experiment method (DOE). The results indicated that the two materials were joined by a mechanical interlock at an interface line, without formation of intermetallic compounds. The shear force of the joint reached an ultimate value of. <italic>482kN</italic>. The shear force of the joint improved by increasing plunging depth of the tool. Samples of minimum shear force value failed by a pull-outing aluminum metal from the carbon steel specimen. Samples of higher shear force value exhibited a shear mode of fracture. Increasing the rotating speed and decreasing pre-heating increased the process temperature.</p> </abstract>ARTICLEtrue Numerical Approximation of 2D Coupled Burgers’ Equation Using Modified Cubic Trigonometric B-Spline Differential Quadrature Method<abstract> <title style='display:none'>Abstract</title> <p>In the present paper, trigonometric B-spline DQM is applied to get the approximated solution of coupled 2D non-linear Burgers’ equation. This technique, named modified cubic trigonometric B-spline DQM, has been used to obtain accurate and effective numerical approximations of the above-mentioned partial differential equation. For checking the compatibility of results, different types of test examples are discussed. A comparison is done between <italic>L<sub>2</sub></italic> and <italic>L</italic><sub>∞</sub> error norms with the previous, present results and with the exact solution. The resultant set of ODEs has been solved by employing the SSP RK 43 method. It is observed that the obtained results are improved compared to the previous numerical results in the literature.</p> </abstract>ARTICLEtrue and Mass Transfer in a Vertical Channel Flow Through a Porous Medium in the Presence of Radiation<abstract> <title style='display:none'>Abstract</title> <p>An analysis is made of heat and mass transfer in a three dimensional flow between two vertical porous plates through a porous medium. Analytical solutions have been obtained using the perturbation technique. The effect of non-dimensional parameters on velocity, temperature and concentration field are shown graphically. It is seen that the main flow velocity decreases with an increase in both the radiation parameter and Schmidt number but increases with an increase in the thermal Grashoff number, mass Grashoff number as well as the permeability parameter. Variations of the shear stress at the left plate are given in a tabular form. It is seen that the shear stress due to the primary flow at the left plate increases with an increase in the Reynolds number but decrease with an increase in the Schmidt number. With the increase of both the radiation parameter and Reynolds number the temperature decreases. The concentration field also decreases with an increase of the Schmidt number. Variations of mass flux at the left plate are given in tabular form. It is seen that the mass flux at the left plate increases with increase in both Schmidt number or Reynolds number.</p> </abstract>ARTICLEtrue of Velocity and Acceleration Effect on Mecanum Wheel Robot Positioning<abstract> <title style='display:none'>Abstract</title> <p>In this paper, a Mecanum wheel omnidirectional robotic platform made for taking measurements in harsh and dangerous conditions is introduced. Due to the necessity of highly accurate displacement of the platform for measuring the conditions at the exact measurement point and due to known Mecanum wheel slippage and relatively poor position accuracy, a calibration procedure for minimizing positioning error had to be implemented. For this task, a highly accurate stereographic digital image correlation (DIC) system was used to measure platform displacement. A series of parameters, namely linear maximum velocity and acceleration/deceleration values, were taken into account during the calibration procedure to find the best combination allowing precise movement of the robot. It was found that low acceleration values were the main causes of the robot’s poor positioning accuracy and could cause the robot’s motors to stall. Max speed values proved to have little effect on the robot’s positioning.</p> </abstract>ARTICLEtrue and Magnetohydrodynamic Effects on Convective Nanofluid Past an Inclined Plate in the Presence of a Chemical Reaction<abstract> <title style='display:none'>Abstract</title> <p>This computational work explores the heat and mass transfer of copper water nanofluid flowing along an inclined plate with varying surface temperature and concentration in the presence of a magnetic field and radiation through a permeable medium. The dimensionless governing equations are solved numerically using an efficient finite-difference technique, which is fast convergent and unconditionally stable. The findings are reviewed and illustrated through graphs for pertinent parameters.</p> </abstract>ARTICLEtrue Reacting Jeffrey Fluid Flow Over a Deformable Porous Layer with Entropy Generation Analysis<abstract> <title style='display:none'>Abstract</title> <p>Entropy generation of a steady Jeffrey fluid flow over a deformable vertical porous layer is analysed with consideration of a first-order chemical reaction and thermal diffusion. The porous material is modelled as a homogeneous binary mixture of fluid and solid phases where each point in the binary mixture is occupied concurrently by the fluid and solid. The combined phenomenon of solid deformation and fluid movement is taken into account. The impact of relevant parameters on the fluid velocity, solid displacement, temperature and concentration profiles is discussed. It is noticed that the Jeffrey fluid parameter enhances the entropy generation number, fluid velocity and solid displacement profiles, but a reverse effect is seen for the Bejan number. Further, entropy generation, fluid velocity and solid displacement reduce due to the higher estimates of the chemical reaction parameter, while the Bejan number enhances.</p> </abstract>ARTICLEtrue