摘要:

The processing of PEEK/graphite fiber composites is characterized by an inordinate amount of hand labor. This greatly increases the cost, time, and inaccuracy involved in production. Automation of the lay-up and consolidation steps are a prerequisite for the widespread application and acceptance of these, as well as all, high performance materials. Automated techniques for the lay-up and consolidation of PEEK/graphite fiber composites have been developed and are presented in this paper. Discrete part lay-up schemes utilize robotic manipulators and specially constructed tables and allow any lay-up configuration to be automatically produced at high production rates. The size of the discrete parts was limited to 4 by 4 meters by design, not by any inherent difficulties. This size can be increased by enlarging the lay-up table. The length of a continuous sheet was limited by the length of the PEEK/graphite fiber prepreg material currently available. Its width was also restricted to 4 meters by design, but also can be increased to the desired width. Continuous consolidation methods were designed for both discrete and continuous parts. Heating is performed by quartz radiative heaters and consolidation pressure is produced by pressure rollers. These processes were designed taking into consideration

ISSN:0884-2558    

DOI:10.1080/10426918708953180

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The advantages of EDM polishing are to be found chiefly in the multidirectional processing of complex volumes without the undercuts which easily arise with manual polishing in tool- and mould-making. A considerable number of individual factors affect the polishing process, with decisive effects on the product quality which can be achieved. Particular importance may be ascribed to such pulse parameters as discharge current, pulse duration, pulse interval, open-circuit voltage and polarity, which must be carefully matched if a shining polished surface is to be achieved

ISSN:0884-2558    

DOI:10.1080/10426918708953181

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A three dimensional model of the BTA deep-hole machining system is presented by modelling each of the components separately and later combining to represent the total system. A model for the interaction between the workpiece and the cutting tool is also included. Such a model can determine the response of any component of the machine tool as well as the individual influence on the system performance. Based on this, physical models representing the three working methods in the BTA process can be studied, from which stochastic differential equations are derived to represent the resultant force system on the machine tool

ISSN:0884-2558    

DOI:10.1080/10426918708953182

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In this paper, the solutions to the stochastic differential equations, which mathematically represent the machine tool work-piece system in BTA deep hole machining are presented. The solutions to the parametric stochastic differential equations have been obtained using the well known averaging technique. The non-parametric inhomogeneous equations have been solved using the Fokker-Planck equation. Based on these solutions, the true motion of the tool tip has been described using the maximum, average and minimum deviation curves. These curves predict that helical grooves will be formed on the workpiece and such helical grooves were observed on the workpieces. Also, the maximum, average and minimum values of deviation of the tool tip which is a measure of the roundness error are established. Based on these results an upper bound for the roundness error as a function of depth of hole is derived. The measurement of roundness of the specimens reveals that the experimental values be in the zone predicted by the theory in a finite region. So it can be speculated that the resultant force system is not completely balanced at the pads.

ISSN:0884-2558    

DOI:10.1080/10426918708953183

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0884-2558    

DOI:10.1080/10426918708953184

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0884-2558    

DOI:10.1080/10426918708953185

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Metal forming problems generally involve large plastic deformations. in cold forming most materials have a nonlinear strain hardening behaviour. F.E.M. solutions of. such problems require elastic plastic analysis and an incremental approach. While a number of such approaches exist they require fairly small step size and hence a large computational effort

ISSN:0884-2558    

DOI:10.1080/10426918708953186

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0884-2558    

DOI:10.1080/10426918708953187

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

No manufacturing process is complete until the exterior finish is applied to the manufactured part. For exterior service, an environmentally resistant coating is required. For the worst case marine environment, a new water-based inorganic zinc-rich paint has been developed. It combines advanced physical properties with unusually long corrosion resistance. Details of composition and application are disclosed.

ISSN:0884-2558    

DOI:10.1080/10426918708953188

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor