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Test report no. PLBO/17 crater wear of tips grade SIP, RD176, RD110 and RD184 machining EN9
No full textTests were carried out with tools of grade S1P„ RD1841 RD110 and
RD176 at 600 fpm cutting speed, 0.010 in/rev. feed and 0.10 in. depth
of cut machining EN9 to determine their relative resistance to crater
wear. The performance of the grades was in the ratio S1P-100, RD184-85„
RD110-56 and RD176-53, although with three out of the four corners tested
the performance of RD184 matched that of S1P.
During the tests RD184 was the only grade which had an edge radius
and it is suggested that further tests should be carried out to determine
whether this has any effect on cratering
Flow along tool-chip interface in orthogonal metal cutting
No full textIn recent papers it has been suggested that over part of the toolchip
contact zone the chip does not slide but sticks to the tool, chip
flow taking place by shear within the body of the chip. Sticking
contact is inconsistent with steady state cutting and in this paper a
slip-line field model of chip flow is presented which does not include
sticking contact and which is consistent with the relevant experimental
observations
An annotated bibliography of presentation of information in aircraft cockpits
No full textINTRODUCTION
In the preparation of, this bibliography only data which has been
published after 1940 has been considered. The choice of this 'cut-off'
point seemed, reasonable on two counts: it begins a period when cockpit
displays become more varied and steadily become more complex so that the
pilot's normal capacities increasingly become a limiting factor in the
efficiency of the system: and it was in the early 'forties' that man's
capacities first began to be related explicitly to equipment design.
It would however have been presumptious to consider that no work before
1940 had any relevance; that some current principles could not be supported
or rejected on the basis of pre-war research or practice. But it is
unlikely that the pursuit of earlier work would have added anything to
the information given by Nickles (1958) in A. History of Aircraft Cockpit
Instrumentation1221:19LE. This admirable review is concerned primarily
in showing how each instrument evolved and its purpose, how information
was displayed in the cockpit and the mechanical principles employed. But
it also considers the empirical solution to implicit ergonomic problems
in this area, tracing the manner in which instruments were combined,
simplified and arranged for better presentation. In some measure it warns
against the presumption of ignoring early data for it points out that
the 'recently' evolved principle of grouping instruments in horizontal
or vertical arrays to ease the visual task of the pilot was suggested by
Doolittle in his 'fog flying' experiments in 1929 … [cont.]
Assessment of blasted surfaces: progress report no. 2
No full textIntroduction
Previous work had shown that the conditions of grit blasting markedly
affected the reflectivity of a mild steel surface and that measurement of
reflectivity thus offered a method for the assessment of blasted surfaces.
The increase in reflectivity of a series of blasted specimens was found to
relate to decreasing surface quality and, after metal spraying, to
decreasing bond strength between the base and the sprayed metal. However,
one series of specimens did not show any correlation between reflectivity
and surface quality and it was decided that an examination of a considerable
number of specimens prepared under more carefully controlled conditions was
necessary for the next stage of the work.
The present report gives the results of reflectivity and bond strength
measurements on some 300 specimens of mild steel blasted under a number of
different conditions by three suppliers. Reflectivity measurements again
showed 'that specimens prepared by any one supplier could be placed in a
series of increasing reflectivity, although some difficulties were still
encountered in relating the result of different suppliers. These difficulties
were most marked with specimens blasted with worn grit. However, correlation
between reflectivity, pull-off strength and blasting conditions was good
with the series of specimens provided by two suppliers. The series from a
third supplier has not been fully tested yet, but very little difference in
reflectivity readings has been found
Push-pull fatigue properties of wires in an iridium: 5% tungsten alloy
No full textIntroduction.
The Materials Department at Cranfield was approached by the Platinum
Metals Division of the International Nickel Co. with a view to carrying
out a preliminary survey of the fatigue properties of an iridium-5%
tungsten alloy. This alloy in drawn wire form is intended for future use
in springs subjected to elevated temperatures. For this reason it was
decided to investigate both the tensile and the torsional fatigue properties
of these wires at room and elevated temperature. This report covers the
tensile room temperature properties; subsequent reports will deal with the
torsional and the high temperature properties
Solution of a load diffusion problem by relaxation methods
No full textSUMMARY
The need. to generalise the usual assumptions made in
the analysis of load diffusion problems has been emphasised by
recent experimental work (Ref. 3)1 which has shown the importance
of bending of the edge members. Direct mathematical
solution of the plate problems, which arise, is hardly feasible
and so in this report a numerical solution using the 'relaxation
method' is carried out. Results show the method to be suitable
for design purposes/ but comparison with experiment still shows
the need for further physical generalisations. These will
form the subject of future work
Explicit formulae for ladder 2-ports
No full textExplicit formulae are obtained
for the network functions of ladder
2—ports
A note on an investigation of the surface grinding process with examples of wheel and coolant selection and planning data
No full textThis note deals with an investigation into the establishment of
manufacturing techniques, on a production scale, for surface
grinding, high tensile heat resistant alloy sheet approximately
7 feet by 5 feet. Rigid manufacturing tolerances are demanded
in which surface finish must not exceed 10 micro-inches and
the thickness tolerance is plus or minus 0. 0002 inches.
The information contained in this report applies to the surface
grinding process in general and can be used to aid production
planning, as a correct estimate of wheel life when operating
under set conditions can be made, and the necessary time for
redressing allowed. Results from the work carried out suggest
that it may be beneficial to pass components to be surface ground
under a roughing wheel (Lumsden) type machine, which will set
the constant metal thickness for final finishing. In this way a
correct estimated time could be allowed for the operations
roughing and finish grinding at optimum conditions
A preliminary report on the aerodynamic characteristics of a 40 degrees swept back wing of aspect ratio 4.5
No full textExperimental investigations have been made of the
now characteristics on wings of moderate sweepback.
This note presents the results of the experimental investigation
into the pressure distribution over a swept back
wing, having an aspect ratio 4. 5 and sweep back angle 40°
at quarter chord. A half model technique has been used.
The wing section was R. A. E. 101 (symmetrical) with 6%
maximum thickness and zero camber. Measurements of
chordwise pressure distributions at a number of spanwise
sections were made in the incidence range 2 - 32°. The
experiments were performed at Reynolds numbers of 0. 9 x 10(6)
and 2 x 10(6) (based on geometric mean chord). From these
measurements, lift, drag and pitching moment characteristics
of the wing were calculated
Compensating rest allowances: some findings and implications for management arising from recent research
No full textIn November 1953 a research project was started at the College of Aeronautics to study Work Study rating, rest and fatigue allowances. This project has been carried out under the sponsorship of the Department of Scientific and Industrial Research with counterpart funds made avail¬able through the Conditional Aid Scheme.
At the commencement of this project it was agreed that our special concern would be rest allowances and that we would consider rating only in so far as it became a necessary part of our study of rest allowances.
This report is not intended to present results covering the whole of our investigations. The work carried out by.J. A, C. Williams who was any colleague in research until April, 1956 has been presented in previous reports and these are referred to in our list of references. Mr Williams has been especially concerned with the problem of heat stress and with the determination of a rational basis for Compensating Rest Allowances in relation to known heat loads.
While this report cannot be regarded therefore as comprehensive it is hoped that for the general reader it will, however, cover sufficiently wide ground to justify some of the general conclusions that are reached at the end of this paper