Papers by Author: Y. Guo

Abstract: Tribological properties of ceramic cutting tool materials in contact with wood based materials were studied in this paper by examining how Al2O3-ceramics and Si3N4-ceramics behave in dry sliding experiment in contact with wood-based materials and by comparing their behavior with tungsten carbide material at the same time. It had been found that the ceramics exhibited much better tribological properties than tungsten carbide material, and Si3N4-ceramic performed better than Al2O3-ceramics. The Al2O3-ceramics with an addition of ZrO2 had better tribological performance than the common Al2O3-ceramics in contact with wood-based materials. The tungsten carbide had better tribological performance than ceramics in tribological contact with wood flour/PE material. A well-marked difference occurred in various cutting materials/MDF frictional pair, but the differences in various cutting materials/PB frictional pair were insignificant. An increase of the normal force didn’t result in any significant decrease of the friction coefficient. An addition of ZrO2 in the Al2O3-ceramics could inhabit corrosive wear.

Abstract: A new method for order tracking filtering of rotating machinery based on instantaneous frequency estimation and zero-phase distortion digital filtering is proposed. Compared with the traditional methods for order tracking filtering, the new method has a number of attractive features such as tacholess, no hardware-based tracking filter and no frequency shift to the original sampling data. The theorems and algorithms of the method are discussed. Filtering of overlapped data blocks, used to restrain the edge effect, which is caused by digital filtering, is introduced. An actual test example of run-up and coast down vibration of a motor is presented to demonstrate the validity of the method.