bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Precision Manufacturing and the British Economy
Authors: McKeown P A 
Published: February 2007

In Industry Year, this James Clayton Lecture appropriately addresses the field of manufacturing engineering and aims to contribute to a wider understanding of how our economy and standard of living critically depend on those who design, manufacture and sell the products of high quality necessary to compete in world markets. The two main thrusts worldwide, in manufacturing engineering are: Automation—in particular, computer integrated, flexible manufacture to reduce overall cost and lead time and in which CADCAM, FMS and CIM are crucially important technologies Manufacture with higher precision—on which a wide range of advanced technology products are totally dependent—and in which precision engineering, micro-engineering and nanotechnology are generally less well understood and practised than by our main international competitors The paper traces recent developments in precision engineering in general and several new and non-conventional high precision ‘machining’ processes in particular, including those by which ‘atomic-bit machining’ is possible. Principles and modern techniques for controlling the accuracy of tool to workpiece in two- and three-dimensional work-zones of high precision production machines are reviewed and illustrated. Today's precision engineering, which can be defined as work at the forefront of design and manufacturing technology, can also be expected to become the general engineering of tomorrow. Its importance to the future of the UK economy cannot be overstated.
A Constrained Optimization Technique to Improve the Performance of Strain Gauge Transducers
Authors: MacCarthy B L , Sharp J M , Burns N D 
Published: February 2007

An optimization strategy is developed to improve the performance of strain gauge transducers. For a specific transducer configuration, the method used is to select an output characteristic to be optimized and to set realistic constraints on the remaining output characteristics and on physical dimensions. Using this strategy, a non-linearly constrained optimization problem may be formulated mathematically. Numerical methods to solve problems of this type are discussed and practical details arising from their use are considered. Correctly formulated problems are solvable quickly and efficiently with routines which are generally available. The techniques introduced here are applicable to a wide range of design problems in transducers of this type and provide a significant design aid.
Design and Construction of the Nchanga Copper Tailings Leach Plant Stage 3
Authors: Hampsheir P R 
Published: February 2007

The Nchanga Division of Zambia Consolidated Copper Mines Limited (ZCCM), the largest producing copper mine in the Commonwealth, has recently commissioned a new plant for reprocessing copper rich tailings. The tailings, some 140 million tonnes in total, are stored in large paddock dams. This paper records the problems and successes involved in completing the design, procurement and construction of the project, on time and ten per cent below budget. Design and project management was by Zambia Engineering Services Limited in Ashford, Kent, a subsidiary of ZCCM, and project funding was from a consortium of international hanks, export credit agencies and development organizations. The subjects dealt with include process design, project capital and funding, management, design and the use of models, estimating and cost control, planning, purchasing and procurement, construction and commissioning. The paper also highlights the problems associated with funding a new project of this type in the Third World in a depressed metals market, and the role of engineering in overcoming financial delays and transport problems. Commissioning started in April 1986 and the plant is now coming up to full production with a few, but not unexpected, problems bearing in mind the size and complexity of the plant. With the addition of stage 3 to the tailings leach plant at Nchanga throughput of ore is increased from 850 000 tonnes/month to 1500 000 tonnes/month and copper output by 40 000 tonnes/annum for a total cost of $250 M.
The Reduction of Gear Pump Pressure Ripple
Authors: Edge K A , Lipscombe B R 
Published: February 2007

Pressure fluctuations in a hydraulic system may be substantially reduced by cancelling the flow ripple produced by the pump. This paper describes a secondary flow ripple generating mechanism which introduces an equal and opposite flow fluctuation to that generated by the pump. Tests have shown that the mechanism can virtually cancel four harmonics of pressure ripple but success is dependent on an accurate knowledge of the pump flow fluctuation characteristic. This is best determined experimentally. Similar improvements can be achieved using a mechanism in a motor. This has the additional benefit of reducing torque fluctuations. The reduction in gear pump pressure ripple achieved with the mechanism has been shown to reduce overall airborne noise levels from a hydraulic system by as much as 10 dB, although the airborne noise radiated from the pump casing was not affected.
Thermodynamic Design of Stirling Cycle Machines
Authors: Organ A J 
Published: February 2007

When local, instantaneous departures from ideal reversible behaviour are evaluated in terms of the entropy generation rate, the differential equations describing the unsteady processes in the Stirling cycle machine give way to steady flow forms. A simple multiplication by To gives immediately the local, instantaneous rate of loss of available work. The paper exploits this fact to obtain, from an ideal model of the flow processes, the indicated cycle work of the real (irreversible) cycle. The result is of the form: [Formula: see text] {( geometric parameters), τγ, NRE, NPR, NF, … ( dimensionless groups in order of diminishing influence)} where τ, NRE, NF etc. are dimensionless groups of the operating parameters, engine speed, pref, Te, Tc etc. and γ is the specific heat ratio of the working fluid, which is shown to be the only fluid property that independently influences Z. The approach is an alternative to the time consuming solution of the defining differential equations and provides a convenient design tool which has long been lacking in this area. The only assumption additional to those invoked in conventional computer modelling of the Stirling cycle is that actual gas processes do not depart excessively from those predicted by the ideal model of the flow—for example from those provided by the so-called ‘adiabatic’ cycle model.
Manufacturing Quality Assurance—A Systematic and Logic Approach to Effective Engineering Management
Authors: Patel B M 
Published: February 2007

In today's increasingly competitive and diversified business markets, industries are continually striving for a high degree of customer satisfaction through product and service reliability at economical costs. Modern practices are now directed towards the use of harmonized, national and international standards such as BS 5750/ISO 9000 series which provide generic guidelines to developing quality systems as an integral part of successful business management strategies. This paper highlights the management, systems and manpower (human resources) aspects of an organization that can provide effective means of controlling and managing the manufacturing engineering function of quality assurance activities within a company.
The Influence of Process Variables on Load and Accuracy When Forging in a Completely Closed Cavity Die
Authors: Ibhadode A O A , Dean T A 
Published: February 2007

The effect of die design, billet location, billet volume variation, billet geometry, friction and die expansion, on forging loads and forged dimensions are investigated, for solid cylinders forged in completely closed die cavities. Forging tests were carried out on both a 2000 kN mechanical press and a 3000 kN hydraulic testing machine using BS 080M40 steel and commercially pure aluminium. The results show that the above factors can significantly affect forging load requirements and die cavity filling. They provide a basis of information for commercial development of net-shape or near-net-shape forging processes.
The Evolution of Locomotive and Rolling Stock Maintenance Schedules
Authors: Butler A W 
Published: February 2007

The paper introduces the maintenance schedule as an integral part of the controls for planned maintenance and reviews the historical development of locomotive maintenance schedules and specifications within British Railways (BR). The events which led to the publication of maintenance schedules for locomotives and rolling stock in a variety of formats and content are explained, culminating in the 1985 decision to produce all such future documents to one standard, taking account of simplification of use at BR depots, the new maintenance policy and the benefits of computerization. The purpose of the maintenance schedule and its supporting documents is redefined in relation to the new maintenance strategy of BR and a new rationale introduced. The standard format is confirmed and the mechanisms for ensuring its maintenance explained. Future requirements associated with development of standard job descriptions, decoupling component overhauls from body overhauls assisted by a computerized maintenance schedule and the changes in overhaul specification promoted by BR's developing contract overhaul policy are described in detail.
Stability of Feedback Control of Boost in Variable Geometry Turbocharged Automotive Diesels
Authors: Backhouse R J , Franklin P C , Winterbone D E 
Published: February 2007

This paper is concerned with the control of turbocharged automotive diesel engines fitted with variable geometry turbines, in particular, for the case where a feedback loop is used to control the boost pressure. Interaction between the loops governing speed and controlling boost will affect the stability of the overall system. The effect of this interaction is considered for the case of automotive diesel engines in the 200–250 kW class at peak torque speed, both with and without engine speed governing, and for the cases of idle and maximum speed governing. The effects of vehicle load, turbo-charger rotor inertia and actuator response are also considered. The analysis uses the characteristic equation of the control system to determine lines of system instability in the gain plane.
The Geometry of the Knee in the Sagittal Plane
Authors: O'Connor J J , Shercliff T L , Biden E , Goodfellow J W 
Published: February 2007

A geometric model of the tibio-femoral joint in the sagittal plane has been developed which demonstrates the relationship between the geometry of the cruciate ligaments and the geometry of the articular surfaces. The cruciate ligaments are represented as two inextensible fibres which, with the femur and the tibia, are analysed as a crossed four-bar linkage. The directions of the ligaments at each position of flexion are calculated. The instant centre, where the flexion axis crosses the parasagittal plane through the joint, lies at the intersection of the cruciates. It moves relative to each of the bones during flexion and extension. The successive positions of the flexion axis relative to a fixed femur and to a fixed tibia are deduced. The shapes of articular surfaces which would allow the bones to flex and extend while maintaining the ligaments each at constant length are calculated and are found to agree closely with the shapes of the natural articular surfaces. The calculated movements of the contact point between the femur and the tibia during flexion also agree well with measurements made on cadaver specimens. The outcome is a geometric simulation of the tibio-femoral joint in the sagittal plane which illustrates the central role played by the cruciate ligaments in the kinematics of the knee and which can be used for the analysis of ligament and contact forces.
Automatic Determination of Work-Holding Parameters for Turned Components
Authors: Hinduja S , Huang H 
Published: February 2007

This paper describes the development of SETUP which is one of the modules of TECHTURN (1), a technologically oriented system for turned components. The SETUP module takes into account the geometrical data of the blank and the component, the technological requirements placed on the component such as surface roughness, concentricity and run-out, and the available work-holding devices for the machine on which the component is to be made. The system automatically determines the following parameters: (a) the work-holding method, that is the use of a chuck, or a chuck and centre or centres; (6) the number of setups required to complete the job; and (c) the clamping positions on the blank and component. In determining this, the system takes into consideration the different clamping devices available on the machine, and their characteristics. If more than one setup is essential, the system tries to balance the stiffnesses of the component in the different setups. This ensures that the stiffness of the component will have a minimum effect when the cutting conditions are calculated. The system can deal with cylindrical blanks as well as castings and forgings, which, often, are of complex shape. To demonstrate the working of the SETUP module, several examples are included.
Repair of Composite Aircraft Parts: An Operator's Viewpoint
Authors: Armstrong K B 
Published: February 2007

This paper discusses the problems of repair experienced by aircraft operators and some actual repairs are mentioned. The use of cold-setting adhesives is compared with the hot-setting pre-pregs recommended by the manufacturers. A need is then shown for more mechanical and physical property data on both the original pre-preg resins and the cold-setting resins that may be used for repair when the provision of hot-curing is difficult.
Manufacturing Machinery in the Computer Era
Authors: Sweeney G 
Published: February 2007

In order to remain competitive in demanding markets, industrial companies have to continue to reduce their dependencies on specialized machinery of relatively limited capabilities and introduce general-purpose machines and modules which can be reprogrammed centrally and/or locally. A review of the type of work required, together with the responses of some manufacturing companies, academic establishments and governmental bodies to this challenge, are the subjects of the present article.
Twenty-First Century Truck Electronics—Today's Global Challenge
Authors: Aravosis G D 
Published: February 2007

The main catalyst for use of state-of-the-art electronics in commercial trucks in the United States is the need to meet EPA emission standards for the 1990s. Important secondary catalysts are fuel economy, anti-lock brake systems and fleet/driver expectations. There are also myriad other forces related to safety, maintainability, servicing and communication which will be satisfied once electronic systems are installed in trucks. The principal economic justification for incurring the cost of electronics at this time is to satisfy these more stringent gaseous emission and particulate regulatory standards. Using electronics, these standards can be met without producing a severe reduction in fuel economy while, as a by-product, interfacing with other truck components, such as brakes, transmissions, safety controls etc. This paper will address the applications of electronics today for diesel engine controls as well as the applications of electronics in areas such as smart power switches, anti-jackknife controls, voice-recognition systems and other future system applications. The exploding use of electronics in trucks will require solutions to many complex problems which are not unique to any one company, geographic area, country or technical society.
Training for Design for Manufacture
Authors: Donovan J R 
Published: February 2007

This paper identifies how training for design for manufacture has needed to change dramatically to best serve the demands of a modern competitive business. It highlights the issues of organization for design and the use of teams to achieve cross-functional integration. The style and content of the training is described to achieve the best use of people working as teams and to provide the knowledge required to operate the design process for competitive success. The structure of the design process is detailed and forms the structure for the training workshops to follow.
The Optimization of Dimensions of an Adjustable Mechanism for a Packaging Machine
Authors: Daadbin A , Sadek K S H 
Published: February 2007

Mechanisms form the basic geometrical elements of many mechanical devices including automatic packaging machinery, typewriters, textile and printing machinery, and others. A mechanism typically is designed to create a desired motion of a rigid body relative to a reference member by the help of gears, cam systems or spatial linkages. In flow pack machines a tube of wrapper containing the products moves with a uniform velocity, while the reciprocating heads move forward and backwards sealing different products. In an existing machine, these motions are produced by a rather complex mechanism involving cams and adjustable links. The paper suggests replacing these cams by a suitable quick-return mechanism with a minimum number of adjustable links. The dimensions of this mechanism are optimized such that the motions produced are as near as possible to those obtained by the original cam mechanisms. The simplification can result in reduction in the mass of different components and existing forces in the mechanism.
Information Systems for Use by Production Management in Smaller Manufacturing Enterprises
Authors: Muhlemann A P , Price D H R , Sharp J A , Afferson M , Andrews J K 
Published: February 2007

This paper presents the results of a research project designed to investigate the possibilities of developing generic software for use by production management in smaller manufacturing enterprises (SME). This has exploited the latest development in fourth generation languages (4GLs). A survey was carried out to establish the current state-of-the-art in computer assisted production management (CAPM) and to identify key areas to be included in the development. The results of this led to the inclusion of materials management, production planning (imaterials and resources), production progressing and costing as the basic cores in the system developed. The choice of 4GL was seen as a crucial factor to the success of the project. The wide availability of these meant that a formalized procedure needed to be developed to select that used by the project team: DAT AFIT DP4. To facilitate the generic nature of the software, and to contribute to its flexibility, a general model of the production process was constructed, built on control theory principles. The data models were based on this. The problems of identifying the functionality to be incorporated into the cores was overcome by the development of a process ‘template prototyping’ by which a structured stage-by-stage brainstorming framework was employed. The generic software developed has been field tested with collaborators in a variety of modes, including prototyping.
The Effect of Joints on the Transverse Vibration of a Simple Structure
Authors: Dunne F P E , Heppenstall M 
Published: February 2007

Transverse vibration tests were carried out on a cold-drawn mild steel tubular beam containing annular metal-to-metal joints. The tests were also carried out on an unjointed beam of the same dimensions. An axial compressive preload was applied giving a compressive stress in the range of 0–80 N/mm2. Joints between rough turned surfaces, between ground surfaces and mixed joints between both types of surface were used. Dynamic bending stiffnesses of the joints over the range of compressive stress were determined. Stiffness of the turned and mixed joints was found to be proportional to preload. Stiffness of ground joints increased with preload, but not proportionally. Theoretical models were developed to determine joint bending siffness and natural frequencies of transverse vibration of the jointed beams. Predicted values of joint bending stiffness for ground and turned joints were in reasonable agreement with the experimental results.
High-Temperature Lubrication
Authors: Lansdown A R 
Published: February 2007

The maximum temperature at which a mechanical system can operate is often determined by the need for lubrication. The paper considers the various heat sources, ambient temperature, mechanical or chemical inputs, and flash temperatures, and discusses their influence on different types of lubrication. The actual temperature limitations are imposed by physical or chemical changes in the lubricant itself, or by changes in a specific lubrication mechanism such as adsorption. The nature of these types of change is described, together with the dominant importance of residence time on the extent of deterioration. Some actual temperature limits for particular lubricants are listed, and the paper suggests some possible design techniques for extending the upper temperature limits for lubrication.
Operational Experiences with LNG Storage Tanks
Authors: Banfield G R , Fairbairn G W 
Published: February 2007

British Gas has 20 above-ground LNG tanks in service, representing some 250 tank-years of experience. No major incidents have occurred with any of these tanks. Operational problems have been experienced with tanks, bunds, LNG valves and pumps; these have all been overcome without recourse to warming up or decommissioning the tanks. This paper summarizes British Gas's operational experiences, describing, in particular, how problems have been overcome. One above-ground tank has been decommissioned recently, for operational rather than technical reasons. This provided an excellent opportunity for detailed study of the condition of an LNG tank after 14 years of operational service. In addition mention is made of the (now decommissioned) in-ground LNG storage tanks, formerly used by British Gas.
Some Aspects of Gear Tribology
Authors: Snidle R W , Evans H P , Dyson A 
Published: February 2007

This paper reviews work being carried out at Cardiff on tribological aspects of heavily loaded gear tooth contacts. The contacts occurring in high conformity (Wildhaber-Novikov) gears have been analysed to predict the thickness of the lubricant film, and the work has been extended to include a consideration of surface roughness effects in gears of this type. For conventional gears a different rough surface elastohydrodynamic (EHL) analysis has been developed and this shows that roughness features can become almost flattened where they occur within the main EHL contact. Recent work on scuffing research is described and new developments in the search for a physical explanation of this form of failure are discussed.
A Finger Function Simulator and the Laboratory Testing of Joint Replacements
Authors: Stokoe S M , Unsworth A , Viva C , Haslock I 
Published: February 2007

The design of a metacarpophalangeal (MCP) joint function simulator was undertaken and resulted in a versatile machine which offers the facility to apply both dynamic and static loading to a joint, following closely the physiological levels and patterns imposed in vivo. An additional feature was the opportunity to investigate the effect of varying the degree of joint instability. Long-term tests performed on Swanson silastic implants have produced failures of the kind seen clinically, which is very encouraging since it would seem to validate the claim that the simulator successfully imitates the finger function.