Browsing by Author "College of Aeronautics, (Cranfield)"
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Item Open Access Characteristics of the high temperature mechanism of creep and recovery in graphite(College of Aeronautics, 1963-11) College of Aeronautics, (Cranfield)The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army, through its European Research Office. This report, not necessarily in final form, is intended only for the internal management use of the Contractor and the U.S. Department of the Army.Item Open Access Characteristics of the high temperature mechanisms of creep and recovery in graphite(College of Aeronautics, 1962) College of Aeronautics, (Cranfield)The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army, through its European Research Office. This report, not necessarily in final form, is intended only for the internal management use of the contractor and the U.S. Department of the Army.Item Open Access Characteristics of the high temperature mechanisms of creep and recovery in graphite(College of Aeronautics, 1963) College of Aeronautics, (Cranfield)The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army, through its European Research Office. This report, not necessarily in final form, is intended only for the internal management use of the Contractor and the 1.T.S. Department of the Army.Item Open Access Characteristics of the high temperature mechanisms of creep and recovery in graphite(College of Aeronautics, 1962) College of Aeronautics, (Cranfield)The report summarizes the first year's work carried out on an investigation into the high temperature mechanisms of creep and recovery in graphite. This work has been devoted to the building of an experimental apparatus capable of exerting creep loads in the temperature range 2000°C — 3000°C. A full description of the apparatus is given and its further potential discussed. Detailed figures are included on the labour expended together with a summary of property acquired for use on the contract.Item Open Access Characteristics of the high temperature mechanisms of creep and recovery in graphite: part 1(College of Aeronautics, 1963-08) College of Aeronautics, (Cranfield)An apparatus has been developed for determining the high temperature creep and recovery characteristics of graphite by applying torsional stresses to thin-walled tubes. This method has the advantages of a simple stress system, constant stress for constant load, easy rapid removal of load and the independence of the strain measurement from thermal expansion. Torsional, stress-strain curves show a decreasing modulus with increasing temperature from 2000 - 2850°C. The rate of creep in this range is increased by increasing temperature and stress. Recovery rate is not so sensitive to increasing temperature. Using a method developed for metals, where recovery can be subtracted from forward creep, a secondary creep rate is deduced. This rate, when plotted according to the Arrhenius' equation, yields an activation energy for secondary creep of 154 kcals over the temperature range 2100 - 2700°C. These results are critically examined and the future extension of the work discussed.Item Open Access Characteristics of the high temperature mechanisms of creep and recovery in graphite: part 2(College of Aeronautics, 1964-02) College of Aeronautics, (Cranfield),The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army throlleh its European Research Office. This report, not necessarily in final form, is intended only for the internal management use of the Contractor and the U.S. Department of the Army.Item Open Access Characteristics of the high temperature mechanisms of creep and recovery in graphite: part 3(College of Aeronautics, 1963-04) College of Aeronautics, (Cranfield)The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army, through its European Research Office. This report, not necessarily in final form, is intended only for the internal management use of the Contractor and the U.S. Department of the Army.Item Open Access Comparison of PERPRO tools grade N5 and N10 against grade N5D and N10D(College of Aeronautics, 1964-02) College of Aeronautics, (Cranfield)Tools of grade N5, N5D, N10 and N1OD were tested to 0.030 in. flankwear when machining EN 9 at a cutting speed of 500 f.p.m. with 0.010 in/rev. feed and 0.10 in. depth of cut. The results showed that there was no significant difference in tool life between the normal grades and the 'D’ grades.Item Open Access Design project 1968/9: management report(College of Aeronautics, 1969) College of Aeronautics, (Cranfield)1. INTRODUCTION The design of an automatic assembly machine with versatility in application was undertaken as a group project by post-graduate students attending a course in production technology. This report summarises the work clone and conclusions reached during the project. In addition there are available five other reports which describe the designing of different areas of the machine in full detail (refs. 1 to 6). There is also the report of a technical survey which was carried out to investigate industrial requirements for automatic assembly. In order that this report may serve as a guide, a summary of the content of each of the other reports is included.Item Open Access Design project 1968/9: report of assembly process committee(College of Aeronautics, 19) College of Aeronautics, (Cranfield)This report describes the approach to the design of an automatic versatile assembly machine of modular construction. Details of the design of the conveyor module, the platen upon which the assembly is mounted and the platen motivation mechanisms are included. It also includes the assembly system that has been applied to the assembly of an electrical contact block. This entailed a machine layout, the re-design of a component and the design and specification of appropriate fixing heads.Item Open Access Four papers contributed by members of the staff and published on the occasion of the 10th anniversary of its foundation(College of Aeronautics, 1956-11) College of Aeronautics, (Cranfield)THE kinetic heating associated with supersonic flight produces temperature gradients within the aircraft structure. These in their turn are responsible for so-called 'thermal stresses' in the components. The calculation of these effects falls into two stages. The first stage consists in the application of the theory of heat transfer to obtain the history of the temperature distribution in the structure. The second stage uses this data to obtain distributions of stress within the structure, resulting from these imposed temperature gradients and proceeds to assess their influence on strength and stiffness. The present paper is concerned entirely with this second stage of the problem and derives basic formulae for the analysis of beam-like structures and components. The results can be applied to wings, fuselages, etc., on the one hand, and to linear reinforcing members like stringers and longerons on the other, in the same way as the usual theories of bending and torsion are applied in the isothermal case. The formulae obtained in this paper represent a generalization of the so-called engineering theory of bending and of the Wagner-Kappus torsion theory to include the effects of non-uniform temperature distribution. Kinematically, allowance is made for overall longitudinal extension, for curvature in two principal planes, for twist and for cross-sectional warping of the kind occurring in Saint Venant's torsion theory. Relationships between end load, bending moments and torques on the one hand and the kinematic parameters on the other are obtained, in a manner modelled on that of Ref. (1), by means of a 'Principle of Stationary Free Energy' established by the present writer in Ref. (2). These results, when combined with the well-known equilibrium equations for bending and torsion, constitute a complete theory of the problem under consideration. Applications to problems of stress analysis are indicated.Item Open Access An investigation of the assembly of transistor cores: first year project 1964/65(College of Aeronautics, 1965-05) College of Aeronautics, (Cranfield)1. Introduction This project was carried out for the Texas Instrument Company of Bedford/ by members of the Ergonomics/ Operational Research and Management sections at Cranfield. Texas Instruments wanted to increase production of doUble alloy transistors by 25%. The increase could not be achieved by hiring extra operators because the amount of floor space was limited. The problem facing the group therefore was one of expanding output by increasing the efficiency and productivity of the existing operators ... [cont.].Item Open Access Proceedings of the work study school conference. Cranfield, March 1954(College of Aeronautics, 1954-06) College of Aeronautics, (Cranfield)The Conference was arranged by request of the students of the Work Study School who attended the three courses. Out of a potential 56 students, 34 attended the Conference, and apologies for their absence were received from most of the remainder. The intention of the Conference was to give students the opportunity of renewing contact with their former colleagues, and to hear reports from people who had been putting Work Study into practice during the previous months, It was generally agreed that the Conference was a success, and arrangements are in hand for such conferences to be held annually.Item Open Access Research on the effect of mixture quality on the exhaust gas emissions of a petrol engine(College of Aeronautics, 1968) College of Aeronautics, (Cranfield)To meet the existing and proposed legislation for the control of air pollution by the exhaust emissions of petrol engines, a major research effort is required within the next five years. Not only are the regulations expected to become more stringent as the number of motor vehicles increases, but improvements will show a diminishing; return in terms of the percentage reduction of emissions when primary factors have been treated. A fundamental problem that is not well understood is the effect of the quality of the fuel-air mixture on combustion in the spark ignition engine. Knowledge of this factor could be important when the emissions are at a low level as a consequence of the employment of devices that treat factors such as mixture strength or the distribution of the fuel. Although the devices are effective in the reduction of the concentrations of hydrocarbons it is thought that many have an undesirable effect on the concentrations of the oxides of nitrogen. To improve the knowledge of these problems, it is the proposal that the research at the Advanced School of Automobile Engineering should be extended to a comprehensive study of the effects of mixture quality on the concentrations of carbon monoxide, hydrocarbons and oxides of nitrogen in the exhaust gas of a spark ignition engine. The facilities at the School are comprehensive and no financial assistance is requested for equipment. To allow the study to be completed within a time that is relevant to the urgency of the problem, a grant is requested for the employment of a Senior Technical Officer and a Laboratory Technician for a period of three years.Item Open Access Research project 1 of the metal spraying and coating Division of the Institute of Welding: progress report no. 1(College of Aeronautics, 1963-08) College of Aeronautics, (Cranfield)Introduction The quality of a sprayed metal deposit is known to be related to the nature of the prepared surface of the base metal. Grit blasting is a common method of surface preparation, and the actual profile or surface contour of the prepared surface can be varied considerably by variation in blasting conditions. The exact requirements of an acceptable surface have never been accurately stated, although a degree of undercut is. considered essential. The object of the present work is to develop a non-destructive method for the assessment of blasted mild steel surfaces in terms of suitability for metal spraying. Such a method needs to combine simplicity and speed, so that it can be used by normal inspection personnel without delaying production. Preferably the method should incorporate a 'failsafe! mechanism.. A number of possible assessment methods have been considered, but attention has been largely concentrated on measurement of the diffuse reflectivity of blasted surfaces. In reality, of course, this is simply an attempt to replace the eye in visual inspection with an instrument, and so remove the human element. Results have been reasonably encouraging, but it is obvious that many more samples need to be examined before a true judgement can be made. Some difficulty has been encountered in deciding the requirements for an acceptable surface. For this reason, a part of the experimental effort has been devoted to the examination of blasted surfaces, and to the measurement of bond strength after metal spraying. A brief review of literature has also been included.Item Open Access Some preliminary suggestions on the standardisation of data collection procedures from U.K. commercial hovercraft operators and an initial study into the derivation of a standard method for estimating the operating costs of hovercraft(College of Aeronautics, 1968-08) College of Aeronautics, (Cranfield)INTRODUCTION This report is a summary of the ground covered during a 6 month pilot study encompassing a number of aspects of hovercraft operations. It is hoped that the experience gained. during this period of study will enable more specific tasks involving much more detailed analysis of particular aspects of operations to be carried out. a) the nature of data available on past operations; b) expected future data; c) topics expected to yield the greatest benefits to all parties concerned (i.e. Cranfiela, Mintech., the Operators and the Manufacturers, present and prospective) both in the short and long term: and a) manpower available. Unfortunately the latter restriction proved more severe than had been initially envisaged. Fields of study considered were as follows: (i) A study of the Problems involved in the derivation of a Standard Method for Estimating the Operating Costs of Hovercraft. (ii) An attempt to Standardise the data collection proceedures from the various current U.K. Operators. iii) An analysis of all currently available data. iv) An investigation into the possible use of Automatic Data Processing techniques for the collection and analysis of operating data. (v) An analysis of the causes and effects of delays and cancellations in current scheduled operations. (vi) A study of the traffic carried on and the demand for current scheduled services, and the effect of varying fare structures on this.Item Open Access Structural testing of wooden aircraft(College of Aeronautics, 1964-12) College of Aeronautics, (Cranfield)For some years now the structural integrity of wooden aircraft of timber and glued plywood torsion box construction has been a matter of concern to the Air Registration Board since it is impossible to assess, by inspection, the strength of an apparently sound glued joint. A programme of testing two representative specimens of two types of aircraft was therefore agreed by the Ministry of Aviation and carried out by the College in conjunction with the Air Registration Board. This report deals with the factual aspects of these tests which were conducted during the period December 1963/February 1964 in the Structural Testing Laboratory of the Department of Aircraft Design.Item Open Access The synthesis of a production information system(College of Aeronautics, 1965-06) College of Aeronautics, (Cranfield)Summary This report outlines a proposed information flow system, capable of giving Management the information necessary to effectively control the Production Organisation of Barretts shoe factory in Northampton. The report specifies the functions of each member of the system and assigns responsibilities to these functions and defines the information required to perform them. The system was designed using the philosophy and techniques of Systems Design.Item Open Access A systems approach to the design of procedures necessary for the organisation of student training flights(College of Aeronautics, 1964-08) College of Aeronautics, (Cranfield)The project was designed to familiarise the group with the use of system design techniques. The objective was to synthesis a system which would be suitable for providing training flights for students at The College of Aeronautics, Cranfield.Item Open Access Test report no. PLBO/10: reducing flank wear by controlled elastic deflection of the tool holder(College of Aeronautics, 1964-04) College of Aeronautics, (Cranfield)Cutting tests were carried out on tips of RD 92, cutting EN9 at 600 fpm, 0.010 in/rev. feed and 0.10 in. depth of cut, with a standard tool holder and with a tool holder which had been modified in such a way as to reduce the contact between the clearance face of the tool tip and the workpiece when the tool holder deflected elastically. The results of the tests showed that up to 0.030 in. flank wear the modified tool holder gave tool lives which were about 20% better than those obtained using the standard tool holder.