Documents published in Scipedia

• Free vibration analysis of pre-stressed FGM Timoshenko beams under large transverse deflection by a variational method

  A. Paul, D. Das

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  A theoretical study on free vibration behavior of pre-stressed functionally graded material (FGM) beam is carried out. Power law variation of volume fraction along the thickness direction is considered. Geometric non-linearity is incorporated through von Kármán non-linear strain–displacement relationship. The governing equation for the static problem is obtained using minimum potential energy principle. The dynamic problem for the pre-stressed beam is formulated as an eigenvalue problem using Hamiltons principle. Three classical boundary conditions with immovable ends are considered for the present work, namely clamped–clamped, simply supported–simply supported and clamped–simply supported. Four different FGM beams, namely Stainless Steel–Silicon Nitride, Stainless Steel–Zirconia, Stainless Steel–Alumina and Titanium alloy–Zirconia, are considered for generation of results. Numerical results for non-dimensional frequency parameters of undeformed beam are presented. The results are presented in non-dimensional pressure-displacement plane for the static problem and in non-dimensional frequency-displacement plane for the dynamic problem. Comparative frequency-displacement plots are presented for different FGMs and also for different volume fraction indices.

  Abstract
  A theoretical study on free vibration behavior of pre-stressed functionally graded material (FGM) beam is carried out. Power law variation of volume fraction along the thickness [...]

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• Effect of welding parameters on pitting behavior of GTAW of DSS and super DSS weldments

  P. Paulraj, R. Garg

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  This work focuses on the effect of welding parameters on corrosion behavior of welded duplex stainless steel (DSS) and super duplex stainless steel (SDSS). The effect of welding parameters, such as heat input, inter-pass temperature, cooling rate, shielding/back purging gas, on corrosion behavior was studied. DSS and SDSS pipes were welded with Gas Tungsten Arc Welding (GTAW) process. After welding, the test samples were non-destructively tested to ensure no defects and test samples were prepared for microstructural examinations and ferrite content measurements. The root region had complex microstructure because of the repetitive heating of the zone during different weld layers. It was observed that at low heat input desirable microstructure was formed. The test samples were subjected to corrosion tests, i.e. ASTM G48 test for the determination of pitting corrosion rate, potentiodynamic polarization tests, and potentiostatic tests to verify susceptibility of the alloys to corrosion attack. DSS weldments had CPT in between 23 °C to 27 °C and SDSS weldments had CPT between 37 °C to 41 °C in potentiostatic measurements. The corrosion test results were correlated to the microstructures of the weldments. The pitting resistance of individual phases was studied and the effect of secondary austenite on corrosion attack was also observed.

  Abstract
  This work focuses on the effect of welding parameters on corrosion behavior of welded duplex stainless steel (DSS) and super duplex stainless steel (SDSS). The effect of welding [...]

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• Dry sliding wear behavior of epoxy fly ash composite with Taguchi optimization

  A. Pattanaik, M. Satpathy, S. Mishra

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  Epoxy resin matrix composite reinforced with fly ash particles was prepared by ultrasonic stirring method. Pin-on-disc wear test of the composite was carried out and compared according to Taguchi design-of-experiment. An orthogonal array exhibited and examined the influencing parameters like % of fly ash debris, typical load, sliding speed and track distance on the composite. Signal to noise ratio analysis optimizes the parametric condition that yields minimum wear rate, minimum frictional force and minimum coefficient of friction. A multi-criteria decision analysis method, TOPSIS is used to optimize the output, and confirmation test has been done to verify the projected model. ANOVA shows that applied normal load plays a vital role in increasing dry sliding wear of epoxy composites.

  Abstract
  Epoxy resin matrix composite reinforced with fly ash particles was prepared by ultrasonic stirring method. Pin-on-disc wear test of the composite was carried out and compared [...]

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• Influence of CaCO3 , Al2 O3 , and TiO2 microfillers on physico-mechanical properties of Luffa cylindrica /polyester composites

  V. Patel, A. Dhanola

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  The development of natural fibre reinforced polymer composites has gained popularity in many applications due to their environment friendly characteristics over the synthetic fibre based polymer composites. This paper describes the fabrication and physical, mechanical, three-body abrasive wear and water absorption behaviour of Luffa fibre reinforced polyester composites with and without addition of micro-fillers of Al2 O3, CaCO3 and TiO2 . The ranking of the composite materials has been made by using Technique for order preference by similarity to ideal solution (TOPSIS) method with output parameters of their physical, mechanical and abrasive wear and water absorption attributes. The addition of microfillers has enhanced greatly the physical and mechanical properties of Luffa -fibre based composites. The addition of microfillers has influenced the physico-mechanical properties of Luffa -fibre based polyester composites in descending order of CaCO3, Al2 O3, and TiO2 .

  Abstract
  The development of natural fibre reinforced polymer composites has gained popularity in many applications due to their environment friendly characteristics over the synthetic [...]

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• State of the art on tribological behavior of polymer matrix composites reinforced with natural fibers in the green materials world

  E. Omrani, P. Menezes, P. Rohatgi

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  Natural fiber reinforced polymer composites have emerged as a potential environmentally friendly and cost-effective alternative to synthetic fiber reinforced composites. Therefore, in the past decade, a number of major industries, such as the automotive, construction and packaging industries, have shown a considerable interest in the progress of new natural fiber reinforced composite materials. The availability of natural fibers and the ease of manufacturing have tempted researchers to study their feasibility of their application as reinforcement and the extent to which they satisfy the required specifications in tribological applications. However, less information concerning the tribological performance of natural fiber reinforced composite material is available in the literature. Hence, the aim of this bibliographic review is to demonstrate the tribological behavior of natural fiber reinforced composites and find a knowledge about their usability for various applications that tribology plays a dominant role. This review presents the reported work on natural fiber reinforced composites with special reference to the type of fibers, matrix polymers, treatment of fibers and test parameters. The results show that composites reinforced with natural fibers have an improvement in tribological properties and their properties are comparable with conventional fibers. In addition, fiber treatment and fiber orientation are two important factors can affect tribological properties where treated fibers and normal oriented fibers exhibit better friction and wear behavior. This review is trying to evaluate the effect of test parameter including normal load and sliding speed on tribological properties, and the results vary based on type of reinforcement. Generally, due to their positive economic and environmental aspects, as well as their good tribological properties, natural composites are showing a good potential for employing in several applications.

  Abstract
  Natural fiber reinforced polymer composites have emerged as a potential environmentally friendly and cost-effective alternative to synthetic fiber reinforced composites. Therefore, [...]

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• Hydromagnetic flow over an unsteady curved stretching surface

  M. Naveed, Z. Abbas, M. Sajid

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  In this study, the boundary layer flow of an incompressible viscous fluid over an unsteady curved stretching surface is investigated in the presence of a variable applied magnetic field. Since the geometry is curved, the basic flow equations of the present problem are modeled using curvilinear coordinates. The obtained system is then reduced into nonlinear ordinary differential equations in two dependent quantities namely the fluid pressure and velocity by introducing suitable transformations. A numerical solution for fluid pressure and velocity is obtained by using a shooting method using Runge–Kutta integration scheme. The effects of various physical parameters on the fluid velocity and pressure distribution are shown through graphs and are discussed in detail. The comparison between the present and the existing results in the literature in special case for flat unsteady stretching, i.e. (K→∞K→∞ ), is found in good agreement.

  Abstract
  In this study, the boundary layer flow of an incompressible viscous fluid over an unsteady curved stretching surface is investigated in the presence of a variable applied [...]

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• Experimental investigation on mechanical and microstructural properties of AISI 304 to Cu joints by CO2 laser

  B. Moharana, S. Sahu, S. Sahoo, R. Bathe

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  Aim of the present work is to investigate mechanical and metallurgical characteristics of continuous wave CO2 laser welded dissimilar couple of AISI 304 stainless steel and commercially pure copper sheets in autogenous mode. Metallurgical analysis of the fusion zone has been done to understand the mixing and solidification behavior. Macroscopic examination has been carried out to observe the macro-segregation pattern of Cu, Fe and Cr rich phases in different zones, and the thickness of HAZ was found to be around 10 µm. The micro-channels formed from the steel side to weld pool describe that the copper solidifies first and provides the nucleation surface for the residual melt to grow. These tubular micro-channels formed may be due to carbide precipitation. The EDS analysis conforms the well mixing of SS and Cu inside the weld pool. The mechanical properties in terms of tensile stress found up to 201 MPa and the fracture are obtained outside the weld zone. Microhardness measurements over the fusion zone have been done to understand the keyhole growth and quenching, solidification sequence and stress distribution over the full area.

  Abstract
  Aim of the present work is to investigate mechanical and metallurgical characteristics of continuous wave CO2 laser welded dissimilar couple of AISI 304 stainless steel and [...]

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• Friction and wear behavior of nitrogen-doped ZnO thin films deposited via MOCVD under dry contact

  U. Mbamara, B. Olofinjana, O. Ajayi, C. Lorenzo-Martin, E. Obiajunwa, E. Ajayi

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  Most researches on doped ZnO thin films are tilted toward their applications in optoelectronics and semiconductor devices. Research on their tribological properties is still unfolding. In this work, nitrogen-doped ZnO thin films were deposited on 304 L stainless steel substrate from a combination of zinc acetate and ammonium acetate precursor by MOCVD technique. Compositional and structural studies of the films were done using Rutherford Backscattering Spectroscopy (RBS) and X-ray Diffraction (XRD). The frictional behavior of the thin film coatings was evaluated using a ball-on-flat configuration in reciprocating sliding under dry contact condition. After friction test, the flat and ball counter-face surfaces were examined to assess the wear dimension and failure mechanism. Both friction behavior and wear (in the ball counter-face) were observed to be dependent on the crystallinity and thickness of the thin film coatings.

  Abstract
  Most researches on doped ZnO thin films are tilted toward their applications in optoelectronics and semiconductor devices. Research on their tribological properties is still [...]

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• Multi-objective optimized fuzzy-PID controllers for fourth order nonlinear systems

  M. Mahmoodabadi, H. Jahanshahi

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  In this paper, the Multi-objective Genetic Algorithm (MOGA) is used to obtain the Pareto frontiers of conflicting objective functions for the fuzzy-Proportional-Integral-Derivative (fuzzy-PID) controllers. The ball–beam and inverted pendulum fourth order nonlinear systems are regarded as nonlinear benchmarks. The considered objective functions for the ball–beam system are the distance error of the ball, the angle error of the beam, and the control effort. For the inverted pendulum system, the objective functions are the distance error of the cart, the angle error of the pendulum, and the control effort, which must be minimized simultaneously. The Pareto fronts are compared with those obtained by Multi-objective Particle Swarm Optimization (MOPSO). Four points are chosen from nondominated solutions of the obtained Pareto fronts based on the three conflicting objective functions and used for illustration of the state variables of the controlled systems. Obtained results elucidate the efficiency of the proposed controller in order to control nonlinear systems.

  Abstract
  In this paper, the Multi-objective Genetic Algorithm (MOGA) is used to obtain the Pareto frontiers of conflicting objective functions for the fuzzy-Proportional-Integral-Derivative [...]

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• A hybrid press system: Motion design and inverse kinematics issues

  M. Kütük, L. Dülger

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  A hybrid machine (HM) is a system integrating two types of motor, servo and constant velocity with a mechanism. The purpose is to make use of the energy in the system efficiently with a flexible system having more than one degree of freedom (DOF). A review is included on hybrid press systems. This study is included as a part of an industrial project used for metal forming. The system given here includes a 7 link mechanism, one of link is driven by a constant velocity motor (CV) and the other is driven by a servo motor (SM). Kinematics analysis of the hybrid driven mechanism is presented here as inverse kinematics analysis. Motion design is very crucial step when using a hybrid machine. So motion design procedure is given with motion curve examples needed. Curve Fitting Toolbox (CFT) in Matlab® is offered as an auxiliary method which can be successfully applied. Motion characteristics are chosen by looking at requirements taken from metal forming industry. Results are then presented herein.

  Abstract
  A hybrid machine (HM) is a system integrating two types of motor, servo and constant velocity with a mechanism. The purpose is to make use of the energy in the system efficiently [...]

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