Improvements in Engine and Power Plant including Reduction in Fuel Consumption, Mechanical Design, Blade Cooling, Lower Vibration, Foreign Object Damage, Oil Consumption, and…
Abstract
Improvements in Engine and Power Plant including Reduction in Fuel Consumption, Mechanical Design, Blade Cooling, Lower Vibration, Foreign Object Damage, Oil Consumption, and Reduction in Overhaul Life, all of which can Contribute in Significant Manner to Lower Operating Costs. Recent engine improvements to reduce operating costs are discussed, including examples of features ensuring low vibration level, low metal temperatures of hot end parts, etc. It is predicted that modern techniques will make more major components capable of lasting the whole life span of the engine, facilitating the replacement of present overhaul procedure by sectional overhaul. A possible way to reduce power plant weight is referred to. It is concluded that further advances towards higher engine performance will be accompanied by economies in many other areas of the power unit.
IN this Paper an endeavour is made to indicate the way in which design has progressed from the complex military piston engine, through the elegant simplicity of a new prime mover…
Abstract
IN this Paper an endeavour is made to indicate the way in which design has progressed from the complex military piston engine, through the elegant simplicity of a new prime mover and then, as technical progress showed how it could be improved, on to the complex modern gas turbine engine.
S. F. Wheatcroft and D. H. Glover, CBE, have been re‐appointed full time members of the BRITISH AIRWAYS BOARD.
THE subject of this Sempill Paper was suggested by The Institution of Production Engineers and I propose to deal with it in two sections. In the first, I shall give an outline of…
Abstract
THE subject of this Sempill Paper was suggested by The Institution of Production Engineers and I propose to deal with it in two sections. In the first, I shall give an outline of current procurement procedures; and in the second, attempt to identify mistakes of the past and offer personal views on some of the areas that need to be tackled more energetically if efficiency is to be improved.
PADIS‐ODE, described in MRN Vol. 3, Nos. 1 and 3, 1980, was developed to allow each separate aspect of any policy decision to be properly worked out in professional studies, and…
Abstract
PADIS‐ODE, described in MRN Vol. 3, Nos. 1 and 3, 1980, was developed to allow each separate aspect of any policy decision to be properly worked out in professional studies, and to provide formal means for communicating meaningfully to others the degree of risk that may remain in any policy as defined.
This paper aims to present an account of the history and recent cultural revival of the Acadians, one people flourishing in two geographically distinct regions of North America.
Abstract
Purpose
This paper aims to present an account of the history and recent cultural revival of the Acadians, one people flourishing in two geographically distinct regions of North America.
Design/methodology/approach
The methodology is a comparison and contrast structure utilizing secondary historical research sources.
Findings
Two different environments have given rise to a similar pattern of development, suppression, and rejuvenation of Acadian and Cajun culture in which apparent differences between the groups hide deeper correspondences, while lesser‐known parallels are more striking than more obvious similarities.
Research limitations/implications
While the particular case of Acadian and Cajun collaboration is unique, future research may compare this case to that of other cultural groups separated by geography and political systems.
Originality/value
This paper suggests that the Acadians and Cajuns are a unique case of two cultures with a single history achieving cultural autonomy first in tandem and finally in concert.
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Keywords
Francis Sabourin and Michel Brunet
The aim of this paper is to present an enriched formulation of a rotation‐free (RF) triangular shell element in order to use it for shells of general shapes while, up to now, it…
Abstract
Purpose
The aim of this paper is to present an enriched formulation of a rotation‐free (RF) triangular shell element in order to use it for shells of general shapes while, up to now, it is limited to shells without branching surfaces and progressive variations in terms of material behavior and thickness.
Design/methodology/approach
The formulation keeps the main characteristic of Morley's element: bending effects can be expressed with three “bending angles” only. But, for a RF element, these angles are defined with the rigid body rotations of the element itself and those of its neighbours. This usual formulation of a RF shell element can be extended provided that curvatures‐displacements relation involves the material characteristics of the element itself and of its neighbours and the same goes for thickness.
Findings
Numerous examples with regular and irregular meshes of structures involving branching surfaces point out convergence and accuracy. Large displacement analyses – including crash simulations – show the effectiveness, too. A deep‐drawing of a “U” shape and the following springback prediction highlight the fact that the curvatures are captured more exactly (when nodes slide on die radius) since they are imposed in terms of translations whereas they are traditionally computed with nodal rotations not managed by contact conditions on the tooling.
Practical implications
The “S3” element detailed here is implemented in RADIOSS® software. The general conclusions are that this triangle often gives almost the same result as “DKT18” but is two times less cheaper and it is found interesting for sheet forming simulations.
Originality/value
Specificity of such an element clearly appears while lifting the initial restrictions quoted before.
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This paper investigates gender differences in reported job satisfaction and career choices revealed by a postal survey of accountants from the Queensland Division of the Institute…
Abstract
This paper investigates gender differences in reported job satisfaction and career choices revealed by a postal survey of accountants from the Queensland Division of the Institute of Chartered Accountants in Australia. Of particular interest are levels of satisfaction with remuneration and promotion. Two moderating factors of career age and firm size are also considered. Consistent with prior research, female accountants reported dissatisfaction with their opportunities for promotion. However, unlike prior research there was no evidence of a gender effect in remuneration levels, and in reported satisfaction with remuneration. Nor were there differences in satisfaction across age bands, and public accounting firms of different size. The link between satisfaction levels of female accountants and their career choices of leaving their current employer, moving to parttime employment, or leaving the accounting profession was also investigated. Consistent with a large body of organisational and accounting research, low levels of job satisfaction were associated with higher turnover intentions for female accountants.
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AT the very outset of this paper it is necessary to make clear that it is not an attempt to compile an exhaustive bibliography of literature relating to special librarianship…
Abstract
AT the very outset of this paper it is necessary to make clear that it is not an attempt to compile an exhaustive bibliography of literature relating to special librarianship. Neither space nor time permit this. In fact, the references given can only claim to be a sample of the wealth of material on the subject and this paper is submitted in the hope that it will stimulate others to more scholarly efforts. Reference numbers throughout this paper refer to items in the ‘Select list of references to the literature of special librarianship’, section 2 onwards.
Francis Sabourin, Jérôme Carbonniere and Michel Brunet
The purpose of this paper is to present a quadrilateral shell element using 16 degrees of freedom (dof) (12 translations and four rotations) which makes a pair with Morley's…
Abstract
Purpose
The purpose of this paper is to present a quadrilateral shell element using 16 degrees of freedom (dof) (12 translations and four rotations) which makes a pair with Morley's triangle at 12 dof. This latter has been updated by Batoz who later proposed an extension to a quadrilateral (“DKQ16”) but only with special interpolation functions for an elastic behaviour of the material. Precisely, it is in order to release from this strong limitation that a completely different formulation is proposed here.
Design/methodology/approach
The development of this new quadrilateral called “DKS16” involves three stages. The first one starts from Morley's triangle updated by Batoz (“DKT12”) to derive a rotation‐free (RF) triangular element (“S3”). The second stage consists in generalising this triangle to a RF quadrilateral (“S4”). During the final leg, the S4 and DKT12 main features are combined to give the quadrilateral “DKS16”.
Findings
Other parameters being equal, the type of finite element chosen for the forming stage simulation has a great influence on further springback result even in software with automatic remeshing. Particularly, it is pointed out that the RF shell elements S3 and S4 as well as the triangle DKT12 are less sensitive to the mesh size than classical shell elements with six dof per node. But, even if some improvements of in‐plane shear have been proposed, stamping codes users are reluctant to use triangles. That is why this paper presents an attempt to extrapolate a quadrilateral (DKS16) from the triangle DKT12 via S3 and S4 elements formulation. Numerous examples showing convergence and accuracy are presented: irregular meshes, large displacement analyses and deep‐drawing simulations.
Practical implications
The triangular “S3” element is already implemented in RADIOSS® software and its implementation – as well as the one of “DKT12” – is in progress in Pam‐Stamp, both as “user elements”. The next step will be the implementation of the quadrilateral “S4” (RF) and, maybe, the element “DKS16” since both are cheaper in terms of computation time and are found interesting for sheet forming.
Originality/value
It seems obvious that curvatures are more exactly captured in RF elements (when nodes slide on die radius) since they are imposed in terms of translations instead of traditional nodal rotations not managed by contact conditions. As the neighbours are involved, a drawback of these RF elements is their complex formulation in case of branching surfaces and/or abrupt variations in material behaviour and/or thickness. This is not the case for elements such as DKT12 or DKS16, good candidates to add to the (long) list of cheap shell elements for large scale computations typical of sheet metal forming.