改进型剪切应力图示法轮胎分析

改进型剪切应力图示法轮胎分析ＪｏｈｎＷ．Ｎｅｗｍａｎ著贺海留编译黄小安校自６０年代后期以来，激光技术就是轮胎制造和翻新过程中致命缺陷与工艺偏差的一种有效检测手段。多年来全息摄影在轮胎脱层、粘合不佳、胎圈区气泡和其它许多有关粘合结构缺陷的检测上一直是最...     

The anodic behaviour of freshly generated α-brass surfaces

Potentiostatic scratching experiments have been carried out on copper and 70-30 brass electrodes in acid and neutral electrolytes. The results are compared with published measurements of stress corrosion crack velocities in α-brass in neutral ammoniacal solutions. The plateau crack velocity at low strain-rates can be accounted for by stoichiometric bare surface oxidation of the alloy components, but at high strain-rates it is necessary to invoke rapid bare surface dezincification. Charge analysis shows that zinc dissolution can occur from several alloy layers at > 5 A cm^?2 without appreciable anodic reaction of copper. Some features of the bare surface electrochemistry of copper are discussed.     

Strategic advantages of interoperability for global manufacturing using CNC technology

In the domain of manufacturing, computer numerically controllers (CNC) technology is a major contributor to the production capacity of the enterprises. The advances in CNC technology coupled with enhancements in computing systems have provided the basis to re-examine the way in which computer-aided systems (CAx) can be used to enable global manufacturing. Interoperability of the various components of the CAx chain is therefore a major prerequisite for manufacturing enterprises for becoming strategically agile and consequently globally competitive. Being interoperable, resources can be utilized interchangeably in a plug-and-produce manner. Over the last 8 years the eminence of a STEP standard for machining entitled STEP-NC (numerical control) has become a well-known vehicle for research to improve the level of information availability at the CNC machine tool. In this paper, the authors introduce the background to the evolution of CNC manufacturing over the last 50 years and the current standards available for programming. A review of the literature in interoperable CNC manufacturing is then provided relating to milling, turn–mill and other NC processes. The major part of the paper provides a strategic view of how interoperability can be implemented across the CAx chain with a range of standards used to regulate the flow of information. Finally, the paper outlines the advantages and major issues for future developments in interoperability, identifying future key requirements and limiting factors.