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This paper aims to illustrate the tolerance optimization method based on the assembly accuracy constrain, precession constrain and the cost of production of the assembly product.

A tolerance optimization method is an excellent way to perform product assembly performance. The tolerance optimization method is adapted to the process analysis of the hatch and skin of an aircraft. In this paper, the tolerance optimization techniques are applied to the tolerance allocation for step difference analysis (example: step difference between aircraft cabin door and fuselage outer skin). First, a mathematical model is described to understand the relationship between manufacturing cost and tolerance cost. Second, the penalty function method is applied to form a new equation for tolerance optimization. Finally, MATLAB software is used to calculate 170 loops iteration to understand the efficiency of the new equation for tolerance optimization.

The tolerance optimization method is based on the assembly accuracy constrain, machinery constrain and the cost of production of the assembly product. The main finding of this paper is the lowest assembly and lowest production costs that met the product tolerance specification.

This paper illustrated an efficient method of tolerance allocation for products assembly. After 170 loops iterations, it founds that the results very close to the original required tolerance. But it can easily say that the different number of loops iterations may have a different result. But optimization result must be approximate to the original tolerance requirements.

It is evident from Table 4 that the tolerance of the closed loop is 1.3999 after the tolerance distribution is completed, which is less than and very close to the original tolerance of 1.40; the machining precision constraint of the outer skin of the cabin door and the fuselage is satisfied, and the assembly precision constraint of the closed loop is satisfied.

The research may support further research studies to minimize cost tolerance allocation using tolerance cost optimization techniques, which must meet the given constrain accuracy for assembly products.

Near-net-shaped processes of jet engine blade have better performance in both reducing the material waste during production and improving work reliability in service, while the geometric features of blade, both sculptured surface and thin-walled shape, make the precise machining of blade challenging and difficult owing to its dynamics behaviors under complex clamping and machining loads. This paper aims to present a fundamental approach on modeling and performance analysis of the blade–fixture system.

A computerized framework on the complex blade–fixture dynamic behavior has been developed. Theoretical mechanic analysis on blade fixturing and machining is proposed with an especial emphasis on the boundary conditions of the blade–fixture system. Then the finite element analysis (FEA) method is used to simulate the variation trend of preloads, stiffness and blade distortion. The strong influence of parameters of workpiece–fixture configuration on blade distortion and machining error is investigated.

With a case of real jet engine blade machining, the experimental results and theoretical predictions suggest good agreement on their variation tendency. The loaded pressure of clamps has a critical influence on the total stiff performance of the blade–fixture system, and the profile error of the blade contributes much to the inconsistency in geometric dimension and surface integrity of blades’ machining. In the end, the results also validate the effectiveness of this methodology to predict and improve the performance of the blade–fixture configuration design.

The adaptive machining of near-net-shaped jet engine blade is a new high-performance manufacturing technology in aerospace production. This study provides a fundamental methodology for the performance analysis of blade-fixture system, to clear the variation law of blade distortion during preloading and machining, which will contribute to minimize the machining error and improve productivity.

MANY indications of the growing importance of work study as an aid to increased productivity will be in evidence at the Third Annual Production Exhibition and Convention (Olympia, May 12–21) where many of the improved methods displayed by upwards of a hundred firms and organisations are the direct or indirect results of the application of work study techniques.

TYPICAL of many successful sub‐contract machine shops supplying precision components to industries such as aerospace, electronics and defence, Broadway Engineering of Bristol, has an established reputation for quality and service based on traditional manual skills. However, increasingly fierce competition over recent years has demanded not only keener prices but also the ability to respond more quickly to changing patterns of demand from the market.

WAHLI machining centres from Switzerland are high precision machining centres with advanced features. There are a number of models already in use in the aerospace industry — in this country with British Aerospace, and overseas with the Thomson Group, MBB, Dassault, Pratt and Whitney and Aerospaciale.

The third in a series giving suggestions for laboratory work on the various types of machine tool

The introduction of new industrial legislation in 1987, in the former Soviet Union, followed a policy of decentralization in which factories were given increased authority to seek their own customers and suppliers, agree prices, and to engage directly in foreign trade. Additionally, from 1987, various forms of co‐operative enterprise and leasing were established, State price controls began to be lifted from many products, and the groundwork was established for a wide range of industrial assets to be converted from public to private ownership. Discusses the major features of technological change and management behaviour likely to occur in the Commonwealth of Independent States, as enterprises continue to operate in an environment of decentralization in which authority and responsibility is being transferred to them from the previous State committees and industrial ministries. Specific attention is paid to the likely effects of this decentralization on markets, innovation and quality within the Commonwealth of Independent States. Details possible changes in supplies, workforce management, and management development as the effects of decentralization are diffused throughout these areas of industrial activity.

The paper reports a study into set‐up time reduction and mistake proofing methods in a small company involved in the machining of precision components in small batches with high variety for the aerospace industry. The company has made some set‐up reductions mainly using work study related methods and in one manufacturing cell by the use of the Single Minute Exchange of Die (SMED) methodology. Mistake proofing devices in the form of fouling pins and offset holes have been developed for the family of components manufactured in this cell. Until recently the set‐up times were not measured and worse still were considered as productive hours. As a consequence, there was a lack of awareness and motivation amongst operational personnel to reduce set‐up times and knowledge of SMED was limited to a small group of individuals. This, along with the lack of investment in mechanisms to aid set‐up time reductions and prevent errors, has restricted the use of this type of methods and technology. However, there is evidence that the demands made by the company’s major customer will lead to increased efforts to put into place these types of changes.