You can read Engineering Tribology a great book by Stachowiak and Batchelor on scribd.
Friday, October 15, 2010
PMD offers fretting analysis
PMD offers analysis of fretting problems using finite element analysis.
Wednesday, September 29, 2010
Friday, September 24, 2010
Little damage of fretting with chromium plates
Fretting wearIn this interview the interviewee says that he has not come across any cases of fretting corrosion with chromium plating. He does not say it won't happen, but its is uncommon.
Wednesday, September 22, 2010
SKF guide about fretting corrosion
SKF has a section on their website dealing with fretting corrosion.
Tuesday, September 21, 2010
Bearing failure modes
Here are some pictures of bearing failure modes. It is interesting and extensive.Fretting Wear
Fretting and tribology for windmills
This Royal Society paper looks like it will be interesting. It discusses wind turbine advancements and has a section on fretting.http://rsta.royalsocietypublishing.org/content/368/1929/4829.short
Saturday, September 18, 2010
Thursday, September 2, 2010
Monday, August 30, 2010
Monday, August 23, 2010
Monday, August 16, 2010
Tuesday, August 10, 2010
Friday, July 30, 2010
Tuesday, July 27, 2010
Monday, July 19, 2010
Thursday, July 15, 2010
Thursday, June 24, 2010
Fretting wear
Fretting wear is one of the leading causes of failure in industrial machinery. As many of the predominant failure modes are dealt with, machines last longer making fretting wear and fretting fatigue a more likely mechanism of failure. The number of incidences of fretting and the number of industries where fretting failures occur has been increasing since the Second World War. Even though more resources are being invested in understanding and reducing fretting, this trend will probably not change in the foreseeable future.
What type of machine is at risk for a fretting failure? Any machine which has vibrations. Any machine which has joints which are nominally fixed although allowing some movement. Fretting is a phenomenon that occurs whenever two contacting bodies experience small scale motion.
The motion required for fretting wear is very small. Although fretting is generally thought of as having motion on the order of microns, it can occur when the magnitude of displacement is only a few nanometers. By this point it should be clear that fretting is a problem which can afflict any industry. The question is not if you have fretting problems, but when your fretting problems become important enough to address.
Fretting is generally addressed using one of two approaches. Either the normal load on the contact is increased along with the coefficient of friction or the normal load is reduced along with the coefficient of friction. The reasoning behind these two opposing approaches is to either prevent motion from occurring or increase the amplitude of motion enough to lubricate the contact.
The dual nature of these approaches to fretting problems means that one must have a good understanding of both the application and theory before trying to solve a fretting problem. There are also many ways in which the two opposing strategies can be implemented; the only limitation of an educated engineer is his imagination (and his budget).
What type of machine is at risk for a fretting failure? Any machine which has vibrations. Any machine which has joints which are nominally fixed although allowing some movement. Fretting is a phenomenon that occurs whenever two contacting bodies experience small scale motion.
The motion required for fretting wear is very small. Although fretting is generally thought of as having motion on the order of microns, it can occur when the magnitude of displacement is only a few nanometers. By this point it should be clear that fretting is a problem which can afflict any industry. The question is not if you have fretting problems, but when your fretting problems become important enough to address.
Fretting is generally addressed using one of two approaches. Either the normal load on the contact is increased along with the coefficient of friction or the normal load is reduced along with the coefficient of friction. The reasoning behind these two opposing approaches is to either prevent motion from occurring or increase the amplitude of motion enough to lubricate the contact.
The dual nature of these approaches to fretting problems means that one must have a good understanding of both the application and theory before trying to solve a fretting problem. There are also many ways in which the two opposing strategies can be implemented; the only limitation of an educated engineer is his imagination (and his budget).
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