Impact Analysis of the Flexural Rigidity on the Frequency and Tension of the Stay Cable

Research and practice show that frequency method is still the most practical and accurate method among all kinds of cable force measurements. Based on the classical string vibration theory, the finite element model of stay cable was created, and a method of iteratively computing stay cable balance curve considering with flexural rigidity was proposed. How dose the flexural rigidity affects the balance curve of stay cable was discussed, and the changing curves of the distance-to-sagging ratio following the pull-to-bend ratio were plotted, which indicated the bigger flexural rigidity, the smaller sagging. 25 pairs cable modality of Xichang cable stayed bridge were accurately analyzed, mode crossover was testified by finite element method, changing curves of frequency and mode shape following the cable force were separately plotted, and changing rule was induced, practical cable force computing method was given. Frequency difference is suitable to judge the rank of actual measurement frequency, and the second frequency is recommended to compute cable force. Engineering instance analysis testified, the method of practical cable force measurement could rule out errors by mode crossover, and be applied to cable with any lengths and any force.

Effect on Gray Balance Caused by Slight Chromaticity Deviation of Paper in Image Reproduction

Gray balance is the basic and critical control parameters of color reproduction, which plays important rule as lever in color reproduction which balance the correlation of material characters and process control parameters. This paper focused on investigation about gray balance data variation caused by slight chromaticity deviation of printing material. In the experiment the creation procedure of gray balance curve was simulated by EPSON Stylus Pro7880c ink-jet printer, and delivered curves were compared with each other. Accordingly the tone value variation of primary color was analyzed in terms of chromaticity deviation of paper. Meanwhile the variation tendency of gray balance impacted by ink and paper property was qualitatively discussed according to data comparison with G7 method. Results show that tone value of Y is so sensitive to paper chromaticity deviation that even the dominant relation between Y and M tone will be altered. At the same time, the more the ink and paper property coincide with ISO standard, the more curve of gray balance curve coincide with theoretically ideal value.