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THIS paper is intended as a sequel to a paper by Dr. J. F. C. Conn entitled “Vibration of a Truncated Wedge” (AIRCRAFT ENGINEERING, Vol. XVI, April 1944, pp. 103–105). The three modes of vibration—longitudinal, flexural and torsional—of a truncated cone encastré at one end and free at the other are considered separately. Special attention is given to the vibration frequencies of the cone and uniform cylinder.

The floating ring generates elastic deformation as the film pressure for high-speed floating ring bearings (FRBs). The purpose of this study is to investigate the influence of ring elastic deformation on the performance of a hydrodynamic/hydrostatic FRB, including floating ring equilibrium and minimum film thickness.

The finite element method and finite difference method are used to solve thermohydrodynamic (THD) lubrication models, including the Reynolds equation, energy equation and temperature–viscosity equation. The deformation matrix method is applied to solve the elastic deformation equation, and then the deformation distribution, floating ring equilibrium and minimum film thickness are investigated. The maximum pressure is compared with the published article to verify the mathematical models.

The deformation value increases with the growth of shaft speed; owing to elastic deformation on the film reaction force and friction moment, the ring achieves equilibrium at a new position, and the inner eccentricity increases while the ring-shaft speed ratio declines. The minimum film thickness declines with the growth of inlet temperature, and the outer film tends to rupture considering elastic deformation at a higher temperature.

The floating ring elastic deformation is coupled with the THD lubrication equations to study ring deformation on the hydrodynamic/hydrostatic FRB lubrication mechanism. The elastic deformation of floating ring should be considered to improve analysis accuracy for FRBs.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0139/

IN a previous paper by the author (‘The Calculation of Frequencies of Vibration of a Truncated Cone’, AIRCRAFT ENGINEERING, Vol. XVIII, July 1946, pp. 235–236) expressions for the fundamental frequencies of longitudinal, flexual and torsional vibrations were obtained. The methods used have now been extended to include the vibrations of truncated pyramids encastré at one end and free at the other, and the results obtained are given in this paper. Special attention is given to the pyramids having equilateral triangle and square cross‐sections.

IN a previous paper (AIRCRAFT ENGINEERING, Vol. XIX, February 1947, pp. 52–4) expressions were derived for the maximum bending moment and shearing force in vessels closed at one end and subjected internally to (a) gas pressure, (b) hydrostatic pressure. The method of solution has been extended in this paper to include the cases of cylindrical vessels, closed at both ends by flat plates or hemispherical shells and subjected to gas pressure.

USING the general theory of cylindrical shells, expressions have been derived for the maximum bending moment and shearing force in vessels closed at one end and subjected internally to (a) gas pressure, (b) hydrostatic pressure. The method has been used by S. Timoshenko (Theory of Plates and Shells, McGraw‐Hill, pp. 412–3) for the special case where one end of the vessels is built into a rigid foundation.

The facility layout problem aims to assign machines/departments to locations and modeled as a quadratic assignment problem (QAP). Multi period facility layout is a special case of this problem where the sum of material handling and re‐layout costs are minimized. Since the problem is proved to be NP‐hard, several exact and heuristic methods are proposed in the literature. The purpose of this paper is to solve the multi period layout problem by using the modified sub‐gradient (MSG) algorithm for the first time and to determine its parameters.

The MSG algorithm can solve a large‐scale of optimization problems that also includes multi period facility layout. Since the performance of the algorithm depends on parameters, a design of experiment is made to determine the appropriate parameter values.

The proposed method evaluates the parameters of the MSG algorithm and most suitable general algebraic modeling solvers. It is observed that the parameter α value and solver type have main effects for small and large size test problems. Further, the results stated that solver type has more influence on large size test problem.

This study is limited with the determination of the MSG algorithm parameters and solver types on the well known small and large size test problems. Further studies may include other test problem results obtained from the presented MSG algorithm parameters and compare them with best known results in the literature.

The paper determines the parameters of the MSG algorithm that is used to solve the multi period layout problem, for the first time in the literature.

The purpose of this paper is to review, evaluate and classify the academic research that has been published in facility layout problems (FLPs) and to analyse how researches and practices on FLPs are.

The review is based on 166 papers published from 1953 to 2021 in international peer-reviewed journals. The literature review on FLPs is presented under broader headings of discrete space and continuous space FLPs. The important formulations of FLPs under static and dynamic environments represented in the discrete and continuous space are presented. The articles reported in the literature on various representations of facilities for the continuous space Unequal Area Facility Layout Problems (UA-FLPs) are summarized. Discussed and commented on adaptive and robust approaches for dynamic environment FLPs. Highlighted the application of meta-heuristic solution methods for FLPs of a larger size.

It is found that most of the earlier research adopted the discrete space for the formulation of FLPs. This type of space representation for FLPs mostly assumes an equal area for all facilities. UA-FLPs represented in discrete space yield irregular shape facilities. It is also observed that the recent works consider the UA-FLPs in continuous space. The solution of continuous space UA-FLPs is more accurate and realistic. Some of the recent works on UA-FLPs consider the flexible bay structure (FBS) due to its advantages over the other representations. FBS helps the proper design of aisle structure in the detailed layout plan. Further, the recent articles reported in the literature consider the dynamic environment for both equal and unequal area FLPs to cope with the changing market environment. It is also found that FLPs are Non-deterministic Polynomial-complete problems, and hence, they set the challenges to researchers to develop efficient meta-heuristic methods to solve the bigger size FLPs in a reasonable time.

Due to the extremely large number of papers on FLPs, a few papers may have inadvertently been missed. The facility layout design research domain is extremely vast which covers other areas such as cellular layouts, pick and drop points and aisle structure design. This research review on FLPs did not consider the papers published on cellular layouts, pick and drop points and aisle structure design. Despite the possibility of not being all-inclusive, the authors firmly believe that most of the papers published on FLPs are covered and the general picture presented on various approaches and parameters of FLPs in this paper are precise and trustworthy.

To the best of the authors’ knowledge, this paper reviews and classifies the literature on FLPs for the first time under the broader headings of discrete space and continuous space representations. Many important formulations of FLPs under static and dynamic environments represented in the discrete and continuous space are presented. This paper also provides the observations from the literature review and identifies the prospective future directions.

This American textbook, originally reviewed in AIRCRAFT ENGINEERING, Vol. xvi, June, 1944, p. 170, has now been made available in Great. Britain, so attention may again be called to it as it provides a practical means of applying analytical geometry to aircraft lofting. The author is head of Engineering Loft' Mathematics at North American Aviation, Inc. He thus occupies a position which has no counterpart in the average British firm, and the book is interesting as an insight into modern American methods.

The new Fair Trading measure aims at the establishment of a strong, bioadly‐based central direction of consumer protection; a new Director‐General of Fair Trading with wide responsibilities “for protecting consumers” with authority to “make proposals for the exercise of order‐making powers in relation to trading practices which adversely affect consumer interests”, and “to act against those who persistently follow a course of conduct unfair to consumers”. This supremo is to work closely with the Monopolies and Mergers Commission and the Restrictive Practices Board, and no less than five junior Ministers are to be given special responsibilities for protecting consumer interests, handling these aspects of the new system in their own departments.

THE problem involved in obtaining satisfactory surface contours for assemblies such as are required in modern aircraft development demands for its successful solution the co‐ordinated, concentrated efforts of all those concerned with both the design and manufacturing processes. Even the casual observer can see that, if optimum performance is to be realized, the external skin or covering, whether made of thin sheet stock or precision machined from heavier plate stock, must be continuously smooth.