bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved Calculation of Sag for a Conductor Supported at Unequal Heights
Authors: Sakala Japhet D.
Published: February 2013

The sag of conductors of an overhead line is determined from the horizontal tension at the lowest point of the conductors. In a conductor supported at unequal heights the lowest point is calculated, together with the horizontal tension, from hyperbolic expressions using an iterative procedure. In practice the hyperbolic functions are usually approximated by their first two terms. While the results are close to the actual values some differences may arise because the approximate methods may not converge to the exact values. The Newton Raphson sag method presented in the paper applies the Newton Raphson method to obtain fast convergence to the exact values. It is inherently more accurate than the classical iterative procedure based on approximating the hyperbolic functions; and the convergence criterion may be set as small as required. The method is also applicable to a conductor supported at equal heights.
Using PSpice for Teaching Output Current Control in D.C.-A.C. Inverters to Undergraduate Students
Authors: Sahoo N. C. , Vejian R. , Gobbi R.
Published: February 2013

In the present day technology of power semiconductor drives, d.c.-a.c. switch-mode voltage source inverters are widely used in a.c. motor servo drives. In these applications, the motor phase currents need to be controlled for high performance. Thus, the prime control issue is to obtain the switching signals for the inverter switches in order to control/regulate the inverter output current. There are various standard ways to derive the switching signals for the inverter. Undergraduate students of electrical engineering should know these basics and get hands-on experience of the inverter current control techniques while taking a course on Power Electronics and Drives. This paper discusses an efficient way of teaching current control in d.c.-a.c. voltage source inverters by computer simulation studies using the student version of PSpice (Release 9.1). Three standard methods have been demonstrated, i.e., triangular carrier method, hysteresis band method, and periodic sampling method. This paper can be used by students for self-study as well as by instructors for simulation-based laboratory experiments.
Review of Soft—Switching Technologies for High—Frequency Switched—Mode Power Conversion
Authors: Ching T. W.
Published: February 2013

Given the rising demand for increases in the switching frequency and efficiency of switched–mode power conversion, the introduction of an undergraduate/postgraduate course on Advanced Power Electronics is both timely and important, and new teaching materials must be designed. This paper presents the evolution of soft–switching technologies, as well as a discussion of operating principles, performance characteristics, experimental results, merits and limitations. The purpose of the new course is to provide the students with up–to–date and comprehensive knowledge of advanced power electronic circuits. Additionally, this paper can help the academic community in developing an intimate understanding of various soft–switching topologies.
Optimal Location of Shunt FACTS Devices in Long Transmission Lines to Improve Transient Stability
Authors: Panda Sidhartha , Patel R. N.
Published: February 2013

This paper deals with determination of the optimal location of shunt flexible a.c. transmission system (FACTS) devices for a long transmission line with pre-defined direction of real power flow. The validity of the mid-point location of shunt FACTS devices is verified with different such devices, using the actual line model. A two-area test system is used to show the effectiveness of off-centre location of the devices in improving transient stability. The results also show that optimal location depends upon the line loading and system initial operating conditions. It is expected that the work will be of use to students as well as researchers studying power system stability and FACTS devices.
On the Proof of the Existence and Uniqueness of Minimum-Energy Control for Linear Time-Invariant Systems
Authors: Bruno Ney , Garcia Jorge Silva , Pellanda Paulo César
Published: February 2013

This paper presents a simple method for determining a minimum-energy input function that takes a controllable linear time-invariant system to any desired state. The method is based upon the idea of formulating the problem as a variational problem under constraint of integral type. The solution is constructive and highly suited to presentation in undergraduate classes in linear systems and control theory, offering a good pedagogical approach for this topic.
An Educational Software Tool for Design of Ferrite EMI Suppressors
Authors: Damnjanovic Mirjana , Stojanovic Goran , Zivanov Ljiljana
Published: February 2013

This paper presents an educational software tool with a user-friendly interface, which can be used in designing ferrite electromagnetic interference (EMI) suppressors. Furthermore, this simulation tool can be used for the calculation of electrical characteristics of these surface-mount components. Ferrite EMI suppressors are made of a conductive layer embedded in a ferrite monolithic structure. They are very successfully used for reducing or eliminating conducted EMI. To design EMI suppressors with optimal characteristics, the student has to choose both appropriate ferrite and conductive material, and the geometry of the inductor embedded in the ferrite material. In this paper the authors describe the modelling and design of EMI suppressors using this educational CAD tool.
GSMSIM: An Educational Simulation Tool for Teaching GSM-Based Mobile Communications in Laboratory Lectures
Authors: García-Díaz Pilar , Salcedo-Sanz Sancho , Portilla-Figueras Antonio , Núñez-Clemente David
Published: February 2013

This paper describes an educational simulation tool, GSMSIM, which has been developed to teach GSM mobile communications in laboratory lectures. The tool has been programmed in OMNET++, a flexible environment which allows its extension to different aspects of GSM technology, such as the simulation of calls, traffic, handoffs, etc. This tool has been used in the courses ‘Communication Systems’ and ‘Telecommunication Networks I’, at the University of Alcalá, Madrid, Spain. We report some of the results obtained in three different scenarios simulating a small, medium and large city, with different characteristics of network coverage.
Electric Power Quality Education and Testing Laboratory with Local Utility Contribution
Authors: Ece Dogan Gokhan , Agalar Sener
Published: February 2013

An education and testing laboratory with local utility contribution for electric power quality (PQ) studies is presented in this paper. The laboratory functions as an instructional and as a research environment for graduate and senior level undergraduate students. The laboratory structure is discussed in terms of system set up and hardware and software tools utilised to conduct the experiments. Automated PQ event detection and classification tools developed by the students are presented to set an example for some of the PQ-related studies conducted in the laboratory. The local utility company contributes to the studies performed in the laboratory by providing unlimited access to the real-life PQ event data acquired by data loggers connected to its feeder lines. The utilisation and importance of this real-life data in PQ education is also presented.
A Top-down Approach to Gaining an Insight into a Transistor Circuit in CS Connection
Authors: Oltean Gabriel , Miron Costin , Şipoş Emilia , Ivanciu Laura
Published: February 2013

This paper explains why and how the very same circuit (a transistor circuit in CS connection) is able to perform multiple applications depending on the use of the transistor in different operating regions. Families of transfer characteristics of the circuit are used to deduce the possible applications. In this way, the emphasis is transferred to understanding the intrinsic operation of a circuit, which opens the perspective for multiple applications, as opposed to the traditional approach, where the emphasis is placed on circuit applications.
A Didactic Comparison of Magnetic Forces
Authors: Sotelo G. G. , Stephan R. M. , Branco P. J. , de Andrade R.
Published: February 2013

The objective of this paper is to present a didactic approach to the calculation of forces generated on permanent magnets, ferromagnetic and diamagnetic materials, superconductors and conductors. A phenomenological view is applied to simplify the understanding needed in undergraduate courses of electromagnetic theory and electric energy conversion. Simple mathematical relations and experiments support the basic concepts.
ATP-EMTP-Based Approach to Teaching Insulation Coordination in the Electrical Engineering Curriculum
Authors: Stojković Saša , Milojević Dragan
Published: February 2013

The paper presents a simulation model of the three final spans and one 110/35/10 kV/kV/kV distribution transformer substation (TS) bay. In order to demonstrate the insulation coordination procedure to students, we used this model to provide simulations of backflash and propagation of travelling waves to substation components. For this purpose, we used ATP-EMTP (Alternative Transients Program) software, which, owing to its user-friendly graphical user interface, can be effectively used for both scientific and educational purposes. Aiming for the modernisation of the Insulation Coordination curriculum, we are proposing modified problem-based learning which combines a classical approach with true problem-based learning (PBL). The pedagogical method and ATP-EMTP simulation model presented in this paper are primarily focused on undergraduate students (the four-year programme), but can also be appropriate at higher levels of education.
A Simple but Powerful Remote Laboratory for Teleoperating Induction Motors
Authors: Calvo I. , Barambones O. , Lopez-Guede J. M.
Published: February 2013

Remote laboratories provide access to hardware devices through the Internet 24 hours a day, becoming a valuable educational tool. This paper focuses on the design and development of a remote laboratory that illustrates the control of electrical machines. There are very good tools available for building remote laboratories. However, most of them require that the instructors have to be skilled in IT. In this paper a very straightforward procedure has been followed to create a simple but powerful laboratory over which students may perform different experiments with an electrical machine.
Software Tool for Estimating the 3D Lightning Protection Zone of High Voltage Substations
Authors: Grujić Aleksandra , Stojković Zlatan
Published: February 2013

This work presents the application of an expanded version of a software tool, formed using powerful AutoCAD software and the programming language Visual Basic, which enables the estimation and visualisation of a 3D lightning protection zone for a high voltage substation (HVS). Various models, methods and protective devices used for protected zone evaluation are discussed. Special attention is dedicated to ground wires as an efficient protective device in forming lighting protection for an HVS. A sensitivity analysis is conducted for a presented 220/110/10 kV HVS protected zone construction depending on the type and dimensions of the protective devices, impulse current magnitude and the various methods. The educational aspects of the application of this software tool are very important for both undergraduate and PhD students studying High Voltage Technique and Computer-Aided Design/Engineering (CAD/CAE) in Power Systems. During the past two academic years, the software application has received favourable comments from students.
High-Resolution DPWM Using Sigma-Delta Modulator Implemented on a Low-Cost Buck Development Board
Authors: Deblecker O.
Published: February 2013

This paper describes project work in which students must implement a pre-processing approach founded on the Σ-Δ technique, which is traditionally well suited to signal processing applications, for increasing the effective resolution of the digital pulse-width modulator in a voltage-mode controlled Buck converter. Simulations in a MATLAB/Simulink environment are first conducted in order to confirm the effectiveness of the approach. Then, experimental results obtained with a low-cost development board are presented and the educational experience is discussed.
Teaching Reliability Analysis of HV/MV Substations and Distribution Feeders Using Educational Software
Authors: Martínez-Lacañina Pedro J. , Martínez-Ramos José L. , Bachiller-Soler Alfonso , Monroy-Berjillos Darío
Published: February 2013

In this paper, educational software for the reliability assessment of high/medium-voltage (HV/MV) substations and distribution feeders is presented. It is a useful tool for learning the utility of reliability indices of the HV/MV substations and their distribution feeders, and their influence on the electrical power system operation. By means of an interactive graphical interface, multiple configurations of HV/MV substation layouts can be selected. The Monte Carlo method and the equipment outages have been used to calculate the expected reliability performance of substations and primary distribution feeders. The proposed educational tool has been evaluated to measure students' satisfaction, and questionnaire and results of this evaluation are presented and discussed.
Integrated Design Optimization and Analysis Using a Spreadsheet Application
Authors: Tai Kang
Published: February 2013

The usual approach in structural design optimization requires that at each iteration of the numerical optimization algorithm, a set of finite element analysis equations are solved to compute the objective/constraint functions. Such a nested solution procedure is straightforward because optimization and analysis processes are kept separate, but wasteful since a complete analysis is performed for each intermediate non-optimal design (one at each iteration). This paper illustrates an economical alternative approach where the finite element equations are formulated as part of the optimization problem by treating the unknowns as design variables and equations as equality constraints. This integrated problem can be solved using a spreadsheet application which serves as a highly suitable platform for integrating and solving the optimization and analysis simultaneously since all spreadsheet cells are interlinked. Together with widely available spreadsheet software, these techniques represent a very convenient tool not just for engineers to learn about the subject of design optimization, but also to gain physical insight into their design problems and perform design optimization routinely in their work.
A Brief Discussion about the Reduction of the Classical Compatibility Equations
Authors: Filipich C. P.
Published: February 2013

The present work arises from a didactic approach to solving the so-called linear elastic problem. It is found that the six classical ‘compatibility equations' (CE) deduced by Saint-Venant in 1864 [1] can be reduced in practice to only three, which are equivalent to the six. Being three, and not the six traditionally presented, and because of the linearity in all the equations involved, the problem of conjuncting equilibrium, compatibility and Hooke's law, becomes a mathematically determined one. The scope of the present paper is essentially academic and mathematical since, in general, the solution of eventual problems using the proposed CE could obviously be tackled by the classical Saint-Venant equations. In the two equivalent groups presented herein all the CE are in terms of the strain tensor components and arbitrary functions.
Twenty Years of Projects on Vehicle Aerodynamics
Authors: White A. S.
Published: February 2013

Reasons for using projects in higher education are briefly discussed and typical aims are outlined. The way projects are operated at Middlesex is described. A variety of student projects in the field of vehicle aerodynamics are illustrated. Projects such as car—caravan drag, roof-rack effects, the performance of go-karts and motor cycles are included. Brief details of the nature of, and results from, these projects are given. They are compared with contemporary reference material. Often despite the small scale of the tests they were surprisingly accurate. Difficulties with managing projects of this nature are outlined. Lessons are drawn from the way students pursued their projects, and tentative conclusions are made about the relevance of this type of project.
The Royal Academy of Engineering Summer School for New Teachers of Engineering Design
Authors: Thompson G. , McChesney C. R.
Published: February 2013

The Royal Academy of Engineering sponsored a one-week Summer School for new teachers of engineering design. The paper discusses the teaching objectives and syllabus of the Summer School and the issues raised and discussed during the week's activities. The intention is that the points discussed in this paper will be valuable for all involved in the education and training of designers.
A Mechanical Engineering Programme Categorized into Curricular Threads
Authors: Mullisen R. S.
Published: February 2013

In order to facilitate useful curriculum deliberations and to satisfy accreditation requirements the undergraduate mechanical engineering programme at this university has been categorized into ‘curricular threads' which represent major themes. Each thread begins at the freshman year and continues through the senior year. The curricular threads and their respective contributions to the programme are: engineering design (12.8%), engineering science (21.4%), engineering analysis (12.4%), engineering support (13.1%), hands-on engineering (9.0%), engineering communication (3.2%), engineering social skills (0.9%), and liberal arts (27.1%). These threads provide useful quantitative information for curriculum evaluation. Other engineering departments may identify alternative threads based on their programme contents. Regardless of the threads used, the organization presented here may serve as a template for the evaluation of individual engineering programmes.
Accurate Simple Equations for Liquid Water Properties
Authors: Liley P. E.
Published: February 2013

Simple algebraic equations are given for the saturation vapour pressure, specific volume, enthalpy and entropy for temperatures of 0(5)30(10)100(25)200 (50)300°C and occasionally over a wider range. Similar equations for the specific heat capacity at constant pressure and an isothermal compressibility function are given for 0–30°C. Interpolating equations for temperatures between 0 and 30°C are given. Estimates of the accuracy of the fittings are usually given.
Modern Methods in the Study of Beam Vibrations
Authors: Pretlove A. J.
Published: February 2013

An assignment is described here in which students undertake both theoretical and experimental analyses of the vibrations of a simple cantilever. A variety of techniques is used, and all of the results are compared. Students are thereby exposed to several features of practical value in the analysis of vibration for design purposes. These include the use of computer-based equipment for experimental data acquisition and analysis, and the value of approximate prediction techniques.
Teaching Rankine Cycle by Using an Intelligent Computer-Aided Instruction Software
Authors: Wu Chih
Published: February 2013

The Rankine cycle plays a very important role in vapour power plants. It is an integral part in teaching courses of engineering thermodynamics. The cycle analysis is long and tedious. It is very necessary to obtain the cycle performance including pump work, heat added, turbine work, heat removed, and efficiency quickly and accurately in the classroom. This paper describes the use of an ICAI (Intelligent Computer Aided Instruction) software in teaching thermodynamics at the US Naval Academy. Historical evolution and several different arranged Rankine cycles can be demonstrated quickly in the classroom. Objectives for improvements, constraints, and consequently design, which cannot be easily accomplished from the conventional teaching, are emphasized. ICAI evokes the intellectual curiosity of students and increases their interest and design ability in thermodynamics.
Teaching Mechanical Design Principles on Engineering Foundation Courses
Authors: Pace Sydney
Published: February 2013

Engineering foundation courses at British universities have been successful in attracting students with diverse academic backgrounds. Such student are often uncertain with regard to career choices within the various engineering disciplines and the reported work describes a means of providing these students with an experience in mechanical design that relates to the challenges of professional practice. A structured, problem solving methodology is presented for the analysis of simple mechanical artefacts that provides a basis of practical experience on which students can devise design proposals for new products. The individual elements of practical and academic skill required to make realistic design proposals and the role of creativity are described. The influence of the school background and student perceptions of design are discussed as factors in the recruitment, retention and motivation of engineering students.
Symbolic Notation of Planetary Gear Trains by Canonical Number Approach (Max Code)
Authors: Madan S. R. , Ambekar A. G. , Jain R. C.
Published: February 2013

In the present work, the concept of ‘Max Code’ approach is used for establishing identification code of planetary gear spur trains. Such a representation provides an expression rather than an unique number. An attempt is made here to establish these expressions for distinct single and two degrees of freedom planetary gear trains. The concept of maximum code (Max Code), as a canonical number is to introduce a symbolic notation for describing two degrees of freedom spur planetary gear trains with the configuration of two central gears, one carrier or arm and at least one planet gear. Properties of canonical number, relevant to kinematic chains, are discussed and an algorithm based on one available in graph theoretic literature exemplifying for establishment of maximum codes of planetary gear-trains. The maximum code being unique and decodable and promises in cataloguing (store and retrieval) of planetary gear trains.
Why the Best Engineers Should Study Humanities
Authors: Ben-Haim Yakov
Published: February 2013

The engineer must operate in a world which uses technology, but neither understands it, or behaves and develops according to patterns familiar to the scientifically trained mind. Three ideas underlie the societal challenges which face the engineer. First, technology influences individuals, society, and the course of history. Second, and conversely, the development of technology is influenced by the cultural and intellectual milieu. These first two ideas emphasize the bilateral interaction between technology and society. The third idea stress that the development of technology is part of the broader development of ideas, attitudes and activities which give any civilization its vital character of growth and change. Engineers should devote some portion of their university years to those disciplines whose goal is to understand the human experience, because it will make them better engineers, more responsible, more creative and effective.
Instrumented Evaporative Cooler: An Experiment in Psychrometrics
Authors: Shakerin Said , Contreras Abraham
Published: February 2013

An instrumented evaporative cooler was developed for use in an undergraduate laboratory in psychrometrics. The air temperature and relative humidity at the inlet and outlet, and the air flow and water consumption rates were measured. Given the experimental data for the inlet air and water, the outlet air properties were predicted using psychrometric equations, and a good comparison was found with the experimental result.
Identifying Nodes and Anti-Nodes of a Longitudinally Vibrating Elastic Rod Carrying a Lumped Mass
Authors: Inceoglu S. , Polat Z. , Gürgöze M.
Published: February 2013

Following a recently developed methodology, the location of the nodes and anti-nodes of a complicated structure can be determined by attaching a virtual element (a lumped mass or grounded spring) to the system of interest and analysing the free vibration of this combined system as a function of the location of the virtual element. The system of an axially vibrating elastic rod carrying a mass in-span has been investigated as an example via the virtual mass approach. In the present study, the virtual spring approach is applied to the same system in order to verify the results of this method.
Concurrent Teaching of Engineering Design, Analysis and Manufacturing
Authors: Tavakoli Massoud S. , Mariappan Jawaharlal
Published: February 2013

In this paper, we first offer a brief overview of the literature on recent efforts in engineering design education, followed by a discussion of the challenges involved with teaching engineering design at an early stage in the curriculum. We then propose an approach utilizing a multi-track teaching style that allows for concurrent teaching of engineering design, analysis and manufacturing. We provide details of how a traditional sophomore-level introductory design course at Kettering University (formerly GMI Engineering & Management Institute) has been modified over the past five years to face pedagogical challenges and accommodate our ideas on the proposed teaching style. The evolution of the ideas, the philosophy behind them and the effects of their implementation on the course are also discussed. Finally, we address teaching quality control, time and budgetary issues.
Analysis of Frictional Forces on a Rigid Body
Authors: Lee H. P.
Published: February 2013

To analyse the motion of a rigid body sliding along a rough surface, information on the point of application of the resulting frictional and normal forces is usually not required. The present study proceeds further, by finding the direction and point of application of the resulting frictional and normal forces on a rigid body in planar motion. These findings are usually omitted in traditional analyses of these problems. It will be shown that such a sliding motion, which is assumed to be feasible with the finding of the acceleration, is not possible for certain combinations of coefficient of friction and geometry of the rigid body. Some interesting findings are highlighted and discussed.
The Design of Tapered Levers
Authors: Miller G. E.
Published: February 2013

Means for rapidly and conveniently treating uniformly tapering levers in terms of deflection, gradient, and lengthway variation of bending stress are given. The optimum taper for material economy in terms of bending stress is derived. Whilst there is no equivalent for deflection, an optimum taper that minimizes deflection for a given quantity of material has been deduced.
Development of a Mass Flow Rate Meter Based on Coriolis Effect
Authors: Sharma Satish C. , Bhattacharya M. , Khaliquzzama Mohd. , Sapra Amar , Khandelwal Lalit K. , Saif Mohd. , Harbindu Rajiv
Published: February 2013

In many process industries, mass flow rate is the desired parameter rather than the volume flow rate. There are two approaches to measure mass flow rate. In the first approach, volume flow rate is measured and then it is multiplied with density. The second approach utilizes the flow metering concepts which are sensitive to mass flow rate. The work presented here falls in the second category. Here, the fluid is made to pass through a vertical U-tube and at the same time it is vibrated by a shaker. The rotary motion produced as a result of vibration causes Coriolis force to act on the tube and causes it to twist. Because of the twisting action, the two limbs of the tube do not pass through the mean position simultaneously. The resulting time lag (Δt) is measured with the help of an 8085 microprocessor and two proximity pick-ups. Mass flow rate is directly proportional to time lag (Δt) and is calculated and displayed subsequently after multiplying time lag (Δt) with a constant of proportionality. The work presented in the paper is carried out as a project assignment by undergraduate students at the final year stage of Bachelor of Engineering degree in Mechanical Engineering. It is expected that the work would be quite useful to the students from the point of view of applying the acquired knowledge to actual engineering situations.
Some Pitfalls with the Elementary Stress Analysis of Struts
Authors: Robinson M.
Published: February 2013

It is shown that the elementary analysis usually adopted when teaching two topics in strut analysis-thermal buckling and the deformation of pin-jointed frameworks, can lead to misleading and/or inaccurate results. This is due to the neglect of post-buckling behaviour and shape imperfections. Some analytical results are obtained which give a clearer picture of the deformation of real structures and can be used in the teaching of undergraduate courses.
Creating Cooling from the ‘Hot’ Sun
Authors: Brown J. Steven , Rashad Ahmed
Published: February 2013

Here we present a project appropriate for mechanical engineering students studying the thermal sciences. In particular, the project is to create cooling from the ‘hot’ sun. To this end, a common cooler was modified so that thermoelectric devices actively cooled it. The electrical energy input needed to power the thermoelectric devices was supplied from a solar panel. This project demonstrates an environmentally friendly methodology for providing air conditioning or refrigeration. In particular, the cooler does not deplete the earth's limited fossil fuel reserves nor does it harm the global environment either by depleting stratospheric ozone or by contributing to global warming through the emission of greenhouse gases. Simple analyses are presented which are used to characterize the thermodynamic performance of the cooler. In addition, some typical experimental results are presented. The project was developed as part of a summer program for secondary school students, whose aim was to encourage the students to consider mechanical engineering as a career. The project can easily be adapted to meet the needs of mechanical engineering undergraduate students studying the thermal sciences.
Tendencies in the Development of Engineering Education versus Industry: A Systematic Approach
Authors: Livshits V. , Sandler B. Z.
Published: February 2013

The rapid development of the technological world has created a tense situation between engineering educators and the ‘engineering consumer’. Industry sometimes develops faster than educators and students are able to respond. This paper considers some aspects of this situation in terms of systemology, indicating certain directions for maintaining adequacy between the systems in cooperation and providing internal homeostatic conditions. Examples are given for predicting bottle-necks in the near future in the relations between practical engineering world and the world of learning.
Thermal Engineering Design Project: A Linear Thermal Expansion Apparatus
Authors: Mullisen R. S.
Published: February 2013

A thermal engineering design project requiring the design, construction, and operation of an apparatus that determines the liner thermal expansion of a slender aluminium rod is described in this paper. The author's design employed a radially constrained and axially free aluminium rod in an electrically heated, copper-tube oven. Thermal expansion was measured with a lever-arm rotating a mirror that reflected a laser beam. A class of junior (third year) mechanical engineering students, working in teams, produced designs using specifically designed air ovens, direct heating with an electric resistance wire wrap, and hot-water baths. Thermal expansion measurements employed dial gauges, dial callipers, micrometers, optical projections including laser beam reflection, and strain gauges. A plot of the accumulated data, comprised of 466 data points, produced a linear curve-fit whose slope gave the average coefficient of linear thermal expansion over the temperature range 20°C to 100°C. Most of the data clustered rather well around the published coefficient of liner thermal expansion line.
Enhancement of Mechanics Education by Means of Photoelasticity and Finite Element Method
Authors: Shakerin Said , Jensen Daniel D.
Published: February 2013

The goal of this project is to enhance mechanics education by incorporating experiments using photoelastic stress analysis and finite element analysis within the existing curricula. Specific instructional objectives for students are to: (a) increase conceptual understanding of stress distribution through photoelastic and finite element based visualization, (b) gain experience with photoelasticity and finite elements including their advantages/limitations, and (c) appreciate the synergism between experimental and numerical methods of stress analysis.

At UOP, one transmission polariscope set, one reflection polariscope set, and accompanying accessories have been purchased and installed for students' use. This equipment has also been used for in-class demonstrations and motivational presentations to high school students. Additional apparatus have been made in-house and/or purchased by departments at UOP and USAFA. All mechanical engineering students at UOP have benefited from this project. Several experiments have been introduced in the curriculum, and several student projects have been completed. A similar combination of photoelastsic demonstrations plus finite element results has been used at USAFA, which has exposed both engineering and non-engineering majors to this educational enhancement.
On the Thermodynamic Cycles of Gas Turbine Power Plants
Authors: Heikal H. A. , Higazy M. G.
Published: February 2013

This paper proposes new appropriate thermodynamic analysis for gas turbine cycles used for power plants rather than that commonly known from the traditional thermodynamic methods. The present analysis is based on using two important design criteria known as the pressure ratio and the temperature ratio. These two criteria are employed to indicate the characteristics of the thermal efficiency and the non-dimensional work. Characteristic charts are established as a function of these two criteria to illustrate the cycles theoretical performance. Appropriate effects of the cycles' regeneration, intercooling and reheat are also discussed. The obtained charts can be used to indicate possible improvement in the thermodynamics of the gas turbine cycles.
A VRML-Java-Based Approach to Teaching APT Programming
Authors: Ong S. K. , Mannan M. A.
Published: February 2013

This paper describes an on-line web-based and computer-based teaching course that has been developed using Information Technology (IT), for use as a supplementary tool in teaching Automatically Programmed Tool (APT) programming. APT is one of the most widely used high-level software tools for complex numerical-controlled machining. APT programming is being offered as one of the third year elective modules in the Mechanical Engineering Department at the National University of Singapore. An APT program is a long series of commands describing the geometry of the work-piece to be machined, as well as the path that a cutter must follow in order to produce the part. HyperText Markup Language (HTML), Java and Virtual Reality Modelling Language (VRML) are the primary languages used to develop this teaching package. They are essential in presenting standard ASCII text and in adding interactivity to the teaching package. They also provide the platform for delivering two-dimensional (2–D) as well as three-dimensional (3–D) work-piece geometry and tool cutting simulations to enhance the understanding and aid in the visualization of the APT language on the Internet. The course content of this elective module has been carefully organized using a combination of linear and hierarchical structures and presented in a series of web-pages to allow students to easily grasp the concepts. Illustrations of a 3–D work-piece as well as the machining path of a cutter are often difficult on a flat 2–D and non-moving piece of transparency. The simulations of machining paths using VRML together with the interactivity offered to the students in visualizing these simulations significantly enhance the students' understanding of the concepts.
On Introducing Engineering Strain
Authors: Williams Harry E.
Published: February 2013

The normal component of engineering strain is identified as the tangential component of the relative displacement of the ends of a line segment divided by the initial length of the line segment. The shear strain associated with a pair of orthogonal line segments is the sum of angles obtained from the transverse components of the relative displacement of the line segments divided by the initial lengths of the line segments.
Design, Build and Test of a Semi-Monocoque Wing Structure
Authors: Farrow Ian
Published: February 2013

A time and cost effective laboratory exercise has been developed to provide large numbers of students with practical hands-on experience of a complete structural development cycle in the first year of their M.Eng. Aeronautical Engineering course. Teams of students are given a set of requirements to design, build and test a small-scale semi-monocoque wing box and centre section structure within a strict schedule. The exercise is assessed by a competitive team component based on structural performance and individual component based on a certification report. The exercise is well received by the students and provides a useful practical experience to relate to other more academic parts of the materials, structures and design courses. The prescribed form, although not covering the conceptual stage of design, provides an instructive layout for students to visualize a complete structural development process clearly despite the inherently large number of problems to be considered and solved.
Buckling Analysis of Laminated Circular Cylindrical Shells Using a Two-Surface Theory
Authors: Huang X. , Lu G.
Published: February 2013

In this paper a simple and efficient method is used for buckling analysis of a laminated circular cylindrical shell based on a two-surface theory. The governing buckling equations are expressed in terms of stress function (φ) and normal displacement (w). These two basic unknowns are solved using double trigonometric series, which satisfy the boundary conditions. The Galerkin procedure is then used to determine the buckling load and buckling mode. Comparison of the obtained numerical results with those given in the literature shows that the two-surface theory gives a fairly good estimate of critical load, especially for shells with thin walls. A slightly revised two-surface theory for non-shallow shells is also presented, which yields a better estimate of buckling load.
How Did Generalized Solutions Arise in Solid Mechanics?
Authors: Lebedev L. P. , Grossi R. O.
Published: February 2013

In recent decades, engineers and physicists have shown an increasing interest in functional analysis and its applications. As many of these practitioners lack special training in mathematics, they sometimes run into trouble when trying to use the tools of this powerful branch of knowledge. Our purpose is to outline the connection between the traditional ideas of mechanics and the newer mathematical concepts of generalized solution and distribution.
Overconsumption as an Ethical Challenge for Engineering Education
Authors: Swearengen J. C. , Woodhouse E. J.
Published: February 2013

One of the most important and yet most difficult of the ethical challenges facing technological civilization is ‘excessive’ consumption in the affluent nations. This includes dissipative use of raw materials and production of waste at rates higher than sources or sinks regenerate. Are design engineers ethically compelled to resist designing new products that abet ‘overconsumption’? Should undergraduate engineering curricula be targeted toward avoiding overconsumption? Technical professionals may be uniquely positioned to work against some aspects of overconsumption, and it is worth inquiring into whether and how the topic might be incorporated into engineering education and practice.
Application of Some Results on Proportionally Damped Systems to a Uniform N-mass Oscillator
Authors: Gürgöze M.
Published: February 2013

A study published some years ago [1] investigated how linear damping affected the eigenvalues of proportionally damped systems, and the results were presented graphically. The necessary conditions for the system to be overdamped or underdamped were given with the help of simple formulae. After a brief summary of the previous work, these methods are applied to a uniform oscillator. With the aid of this simple system, it has been observed that students can comprehend the various types of proportional damping better, and be able to visualize them more easily.
Visual Aid Depicting Mechanical Vibration Systems to Enhance Student Learning
Authors: Hoorfar M. , Najjaran H. , Cleghorn W. L.
Published: February 2013

This paper introduces a program developed for simulation of the mechanical vibration of multi-degree-of-freedom systems with lumped masses. Inputs are system properties and initial conditions, and outputs are displacement and velocity of each mass as a function of time. In addition, the trajectory (i.e., velocity vs. displacement) and animation of each mass may be illustrated. The program can automatically generate physical models with lumped masses from a set of different boundary conditions. In addition, one may input a model with dynamic and static coupling. Previous works on this subject have considered one or a limited number of aspects of mechanical vibration of lumped mass systems [1]. This program, on the other hand, covers most options associated with such systems and it may be considered as a helpful tool on a MATLAB® platform for teaching and understanding of the relevant courses, such as mechanical vibration and automatic control, at the undergraduate level.
On the Curvature of an Euler–Bernoulli Beam
Authors: Kopmaz Osman , Gündoğdu Ömer
Published: February 2013

This paper deals with different approaches to describing the relationship between the bending moment and curvature of a Euler—Bernoulli beam undergoing a large deformation, from a tutorial point of view. First, the concepts of the mathematical and physical curvature are presented in detail. Then, in the case of a cantilevered beam subjected to a single moment at its free end, the difference between the linear theory and the nonlinear theory based on both the mathematical curvature and the physical curvature is shown. It is emphasized that a careless use of the nonlinear mathematical curvature and moment relationship given in most standard textbooks may lead to erroneous results. Furthermore, a numerical example is given for the reader to make a quantitative assessment.
On the Analysis of Small Displacements of Truss Joints
Authors: Dym Clive L. , Williams Harry E.
Published: February 2013

By emphasizing the kinematic aspects and implications of strain in truss analysis, it is shown that joint displacements can be computed in a straightforward manner.
Identification of Parameters W0, n, and D of the Dubinin–Radushkevich Equation
Authors: Nour A. , Tazerouti H. , Ouragh Y.
Published: February 2013

This paper considers a cooling system for a thermal engine using heat from exhaust gas. This system uses a physical adsorption process of solid—gas (active carbon and ammonia). An adsorber tubular element of real scale is submitted to heat flux by electrical air heating, simulating exhaust gas. Temperatures and adsorbed mass are measured. Desorption and adsorption phenomena are described by the Dubinin—Radushkevich model equation, m = W0ρ( T) exp[– D( TIn( Ps( T)/ P)) n], where W0, n, and D are parameters characterising the adsorbent—adsorbate couple. These three parameters can be identified from a simple mite method (using data and models) characterising the adsorbent—adsorbate couple chosen.
Coping with Curvilinear Coordinates in Fluid Mechanics
Authors: Paavola J. , Salonen E.-M.
Published: February 2013

The method of local Cartesian coordinates introduced in the first part of a series of three articles on curvilinear coordinates was applied in the second article to some solid mechanics problems. In this final, third article of the series, the method is applied to fluid mechanics and for intrinsic coordinates. The use of the principle of virtual power is advocated to generate the approriate equations of motion.
A Unique Thermodynamics Course with Laboratories
Authors: Bailey Margaret , Albert Blace , Arnas Ozer , Klawunder Shawn , Klegka John , Wolons David
Published: February 2013

The Department of Civil and Mechanical Engineering at the United States Military Academy (USMA) offers a course in thermodynamics that is well known among the Corps of Cadets, because of its uniqueness and applicability. Students from every department in the USMA enroll in the course and are taught by a faculty that is composed of both military and civilian professors. The classroom and laboratory experiences that have been designed over the past decade provide students with a broad introductory exposure to thermodynamics, while focussing on very relevant applications. This paper presents an overview of the thermodynamic experience created at the USMA and offers several examples of methods to enhance similar courses at other institutions.
Integrating a Research Problem in a Course in Applied Elasticity
Authors: Kaw Autar K. , Besterfield Glen , Nichani Sanjeev
Published: February 2013

An example of integrating a single research problem over a broad range of topics in a graduate-level course in applied elasticity (advanced strength of materials) is given in this paper. The research problem was obtained from an investigation of failures during the assembly of fulcrums of bascule bridges. Topics exemplified by using this problem included interference fits, axisymmetric problems, transformation of strains and stresses, comparison of failure theories, and the effect of temperature-dependent thermoelastic properties.
Applications of Engineering Mechanics in Forensic Engineering
Authors: Musto Joseph C.
Published: February 2013

The inclusion of examples from engineering practice in the classroom is a key to generating student interest and motivation. Ideal examples allow students to apply both concepts from course material and creative problem-solving methodology to a ‘real world’ problem. While open-ended design problems are often used as case studies in upper-level engineering courses, students in the early phases of their academic career often lack the background necessary to handle even simple design case studies with proficiency. Therefore, the practical use of design case studies is extremely limited in first two years of an engineering curriculum, and is limited to trivial exercises or closed-ended parametric optimization problems. As an alternative, case studies involving the investigation and reconstruction of accidents involving engineering systems can be employed. Such case studies allow the students to demonstrate their engineering problem-solving skills, requiring the students to propose a likely accident scenario and prove their scenario using engineering analysis and the formal scientific method. In this paper, the use of forensic engineering case studies in an introductory mechanics course sequence is outlined. Three case studies involving the use of statics, dynamics, and mechanics of materials are presented.