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济钢燃气厂针对济钢转炉煤气储存加压系统的设备现状,组织了一次设备大修,大修后煤气柜升降速度提高到了1.0m/min,并解决了加压机前负压等问题。 相似文献
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Airframe riveting is a critical process that requires high levels of process monitoring and quality assurance due to the very
high risk associated with the failure of such joints. This paper describes the development of the enabling technology developed
for a machine vision-based process monitoring system. One of the key factors affecting the performance of a machine vision
system is the quality of the lighting. In the application described in this paper the available lighting was severely limited
by the confined space in which the system had to operate. The problem was also compounded by the reflective nature of the
objects to be examined. The initial images obtained were not suitable for further processing due to the presence of significant
shadows and specular reflections. A novel solution to this problem based on multiple wavelength illumination and signal processing
is presented along with results from experimental trials of the approach. 相似文献
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The deformation behavior of dispersion strengthened copper alloy Cu-Al2O3 was studied by TEM. The results show that nano-scaled dispersed second phase not only increases dislocation density in matrix, but also has an important influence on the dislocation substructure. The presence of fine dispersed Al2 O3 particles results in a uniform and random dislocation distribution in matrix copper and causes the difficulty in formation of dislocation cell structure and the decrease in the amount of cell structure during deformation. Deformation gives rise to much more dislocations and dislocation cells form more difficultly and the decrease in the cell size with the increase of dispersion degree. 相似文献
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Conceptual damage-sensitive features for structural health monitoring: Laboratory and field demonstrations 总被引:2,自引:0,他引:2
F. Necati Catbas Mustafa Gul Jason L. Burkett 《Mechanical Systems and Signal Processing》2008,22(7):1650-1669
The use of damage-sensitive features to evaluate structural condition or health is a very critical aspect of structural health monitoring. The purpose of this paper is to investigate the potential of two different damage-sensitive features for detecting damage. Different damage scenarios are simulated on a large-scale laboratory structure and a three-span highway bridge for demonstration. The features presented in this paper are the modal flexibility-based deflection and curvature both of which are obtained directly from dynamic properties. In the literature, flexibility associated with mode shapes and mode shapes curvatures have been mostly explored. In this study, multi-input–multi-output dynamic data are used to obtain modal flexibility, which is a close approximation to the actual flexibility. A main novelty is that the curvature is calculated from the deflected shapes using the modal flexibility as opposed to using modal vectors. In this paper, the theory of the methodology is explained and then experimental studies and results are presented. For the experimental studies, the laboratory specimen and the three-span bridge were gradually damaged. It is shown that both deflection and curvature are conceptual and physically meaningful features for damage detection and localization. The issues and the requirements for these features to perform successfully are also presented. 相似文献