Applied Mechanics and Materials Vol. 787

Abstract: High starting force with reduced volume and mass are the primary importance in most of the linear transportation applications. This paper presents a novel tilted Linear Switched Reluctance Motor (LSRM) with reduced mass, volume, force ripple and improved force profile. Three Dimensional (3-D) finite element analyses are carried out on the proposed design to estimate the performance the motor. A thorough comparison has been made between the basic and the proposed structures. Experimental results reveal that, the proposed design is well suited for high starting force applications.

Abstract: Linear switched reluctance motors (LSRMs) are considered for numerous applications because of its inherent properties. The force ripple and hence acoustic noise and vibration make this machine failure in compete with the existing linear induction and linear synchronous machines. In this paper a new type of stator structure is proposed and experimented. The proposed structure provides less force ripple and vibration. Parameters like force ripple and vibration are predicted using finite element analysis (FEA). Experimental results are closely correlated with the predicted results.

Abstract: The regeneration modes of switched reluctance machines are examined in this paper. The conversion of mechanical energy to electrical energy is aided by the stator excitation which is used to provide the air-gap flux and recover the energy from a prime-mover making it suitable for electric/hybrid vehicles. The operation of a C-Dump converter in the generation mode is analyzed and the energy recovery mechanism is illustrated using MATLAB simulations. The braking profile on the prime mover is also examined for multiphase excitation with various currents. The excitation reference is the control variable that is dynamically adjusted to achieve control in the braking mode. A control law is derived to achieve a target speed in the braking mode.

Abstract: TThe growing energy demand in recent years has led to increased use of renewable energy resources. Among all renewable energy sources, the photovoltaic (PV) power generation acts as a green source which is free from greenhouse emissions to provide feasible solution to the increasing energy demand. However the non-linear nature of the solar module, their low-efficiency and high capital cost is being the major hindrance to the penetration and reach of the solar photovoltaic systems. To overcome this non-linearity, this paper presents the implementation of Negative Output Super-Lift Luo converter (NOSLC) with the solar panel. NOSLC is a type of super-lift converter in which the negative output voltage increases in geometric progression. Along with this, to track the maximum power from the PV cell, a technique named Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) is employed. This proposed system is modelled and simulated using MATLAB/Simulink and validated with the theoretical calculations.

Abstract: Recently renewable energy sources have gained much attention as a clean energy. But the main problem occurs with the varying nature with the day and season. Aim of this paper is to conserve the energy, of the natural resources. For solar energy resource, the output induced in the photovoltaic (PV) modules depends on solar radiation and temperature of the solar cells. To maximize the efficiency of the system it is necessary to track the path of sun in order to keep the panel perpendicular to the sun. This paper proposes the design and construction of a microcontroller-based solar panel tracking system. The fuzzy controller aims at maximizing the efficiency of PV panel by focusing the sunlight to incident perpendicularly to the panel. The system consists of a PV panel which can be operated with the help of DC motor, four LED sensors placed in different positions and a fuzzy controller which takes the input from sensors and gives output speed to motor. A prototype is fabricated to test the results and compared with the simulation results. The results show the improved performance by using a tracking system

Abstract: Vibration-based technique to detect damage in laminated composite beams, rectangular plates and cylindrical shells is presented in this paper.A parameter called damage indicator calculated based on mode shape curvature isused in this studyto detect the location and size of small damages accurately in laminated composite structures. Through numerical analysis of laminated compositecantilevered beam, plate and cylindrical shell models with edge crack as damage, the absolute change inthe damage indicator is localized in the region of damage. Thechange in damage indicatorincreases withincreasing size of damage. Thisinformationis obtained by considering two cases of damage sizes (case-1 and case-2)in the structures. Finite element methodbased commercial analysis package ANSYSis used to obtain thenormalized displacement mode shapesof the three models both for intact and damaged states and then the damage indicator is calculated from the mode shapes data.The numerical analysis to detect damage is followed by validation by experimental modal testing.

Abstract: In hard turning, tool wear of cutting tool crossing the limit is highly undesirable because it adversely affects the surface finish. Hence continuous, online tool wear monitoring during the process is essential. The analysis of Acoustic Emission (AE) signal generated during conventional machining has been studied by many investigators for understanding the process of metal cutting and tool wear phenomena. In this experimental study on hard turning, the skew and kurtosis parameters of root mean square values of AE signal (AE_RMS) have been used for online monitoring of a Cubic Boron Nitride (CBN) tool wear.

Abstract: Corrosion, wear and galling resistance under high temperature service conditions are highly essential in nuclear components such as grid plate and diverse safety rod drive mechanism. In order to protect the components from these worst service conditions, hard facing alloys like colmonoy are overlaid on the nuclear components using plasma transfer arc and Gas Tungsten Arc Deposition techniques. Typical defects that occurred during deposition include lack of bonding between substrate and overlay, cracks and porosities. Hence the characterization of such defects is highly essential before using it for the intended application. Conventionally radiography, liquid penetrant testing and ultrasonic testing are used. Radiography cannot detect debonds which are parallel to the surface of the specimen. Though liquid penetrant testing is used for detecting surface cracks, ultrasonic testing could be effectively used in order to characterize highly planar defects which are parallel to the surface. This paper highlights the successful application of immersion ultrasonic testing for characterization of colmonoy overlays. The sample consisted of Colmonoy coating (4-5 mm) on a 316 LN substrate. Ultrasonic examination was carried out using the Immersion Ultrasonic flaw detector. Typical A scans of good region and debonded regions were considered and compared in order to predict the actual location of the defect. In addition B and C scans were also considered for exact characterisation of the defects. Results clearly indicated the superior defect detectability by the use of immersion ultrasonic testing on colmonoy overlays.

Abstract: Inspection plays a major role in any production process. The acceptance or rejection decision of the production lot depends on the inspection results. In recent years, the developments in machine vision techniques have made inspection easier. This paper aims at bottle cap inspection using machine vision techniques. Bottle neck may have defects such as absence of the cap, absence of the tamper ring and improper assembly of cap and tamper ring. This paper deals with checking of the above mentioned defects with a single image of the finished product. This system uses backlight technique. The image of the product obtained using camera is processed using image processing software and then the results obtained are used to accept or reject the particular product. This technique could be implemented in industries for a batch produced series of bottle coming in a conveyor. By using machine vision techniques it is ensured that not even a single defect related to bottle cap is left from observation. Thus the bottle cap inspection becomes easy, accurate and done in less time.

Abstract: The Image processing technique incorporates human perception and intelligence which makes this field more interesting to the research community. The edge detection process is the most important step in image recognition system. In this paper a simple three dimensional model is created by taking the best edge detected image followed by comparison with various edge detection techniques using Labview software. HereCatia model of spur gear isdrawn by observing and analysing best suited edge detected image in order to make the design more precise in edges and geometry and also to make object recognition simple and further scope is given to design a Catia model using dimensional parameters with the help of vision assistant tool.