• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.3
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• pp.636-645
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• 1990

Analytically induced wear mechanism of elastic body under Hertzian contact is applied in acutual wear test of ceramics. There are two types of wear in ceramics, a large scale wear and a small scale wear. The large scale wear is commensurable with Hertzian contact area and the small scale wear with real contact area. Nondimensional parameter, S$_{c}$, is introduced and fully examined to estimate or predict wear rate of ceramics. Ceramic wear for S$_{c}$.leq.0.8 is in small scale wear and for S$_{c}$;geq.1.6 in large scale wear. wear.

• Tribology and Lubricants
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• v.8 no.2
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• pp.35-43
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• 1992

취성재료의 마멸천이기구를 규명하기 위해 반무한탄성체상에 표면균열이 존재할 때 그 위를 헤르쯔 접촉하중이 이동할 경우를 해석모델로 하여 선형파괴역할을 도입하여 해석하였다. 해석방법으로는 표면균열을 인상전위의 연속분포로 치환하여 Erdogan-Gupta의 방법으로 균열끝면의 응력확대계수를 구하여, 취성재료의 균열전파조건인 Erdogan-Sih Criterion을 사용하여 그 전파특성을 해석하였다. 본 논문에서는 마멸율이 적은 마멸에서 마멸율이 큰 마멸로 전이할 때 급격한 표면손상과 마찰계수의 급격한 증가를 동반하므로 이에 대한 해석에 중점을 두었다. 해석결과는 접촉하중과 마찰계수의 증가는 표면균열의 전파를 야기시켜 대규모 마멸입자를 생성시키게 됨을 보여주었다.

• Journal of the Korean Society of Safety
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• v.12 no.4
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• pp.214-219
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• 1997

The mechanical seals, which are installed in rotating machines like pump and compressor, are generally used as sealing devices in the many fields of industries. The failure of mechanical seals such as leakage, crack, breakage, fast and severe wear, excessive torque, and squeaking results in big problems. To identify abnormal phenomena on mechanical seals and to propose the proper monitoring parameter for the failure of mechanical seals, sliding wear experiments were conducted. Acoustic emission, torque, and temperature were measured during experiments. Optical microstructure was observed for the wear processing after every 10 minute sliding at rotation speed of 1750 rpm and scanning electron microscopy was also observed. Except for the initial part of every experiment, the variation of acoustic emission was well coincided with torque variation during the experiments. This study concludes that acoustic emission and torque are proper monitoring parameters for the failure of mechanical seals. The intensity of acoustic emission signals is measured in root mean square voltage. Temperature of sealing face will be used as a parallel parameter for increasing the reliability of monitoring system.