Papers by Keyword: Crack Observation

Abstract: Polymer bearings are widely used under certain environments due to the advantages on light weight, low friction coefficient, high corrosion resistance and electric insulation. The main reason for polymer bearing failures in water was formation of flakings due to crack propagation. However, the mechanism of fatigue crack propagation in polymer material under rolling contact condition has not been clearly explained yet. In the present study, detailed crack observations were made on cross sections along both radial and rolling directions after RCF (Rolling Contact Fatigue) test in water using PPS thrust bearings.

Abstract: Considering the advantages on light weight, low friction coefficient, high corrosion resistance and electric insulation, polymer bearings are widely used under certain environments, where the toughness like metal bearings is not necessary. In our previous study, it was concluded that the main reason for PEEK thrust bearings failure in water was flaking due to surface crack propagation. In the present study, crack observations were made on groove surfaces and cross sections along both radial and rolling directions in order to find the relation between cracks and flaking failures.

Abstract: Acoustic emission (AE) techniques are extensively applied to a variety of fields including civil engineering. Now a new generation of AE techniques, which are able to register and process AE data in real-time, has appeared. Still, there exist some problems to correctly interpreting these data and to completely understand the meaning of AE parameters. In order to solve this, several AE waveform and spectral parameters are investigated, based on an experimental study of concrete and reinforced concrete structures.