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Homework 1
Introduction to Tribology
Answers
1
Investigate, describe and explain the meaning and origin of the word ”Tribology”.
Answer.- The word tribology comes from the greek word for ”rubbing” (τ ριoς). The
literal meaning of the word is ”science of rubbing”. The term was coined and adopted in 1966
as result of the Jost report England (a UK government committee charged with studying
the impact of friction and wear to the economy and society).
2
Do some research and produce an estimate of the fraction of the USA GDP that is wasted
because of friction and wear and how much of it could be saved just by applying existing
tribological knowledge.
Answer.- The Jost report concluded that at least 1 percent of the GNP of the UK could
be saved just by applying existing knowledge about friction and wear and that the potential
for much bigger savings existed. The following table summarizes some of the findings from the
report regarding potential savings to UK industry from application of tribological knowhow.
1
Item
Reduced energy consumption
Reduction in manpower
Reduction in lubricant costs
Reduction in mantenance/replacement costs
Reduction due to reduction in breakdowns
Reduction due to increased availability/efficiency
Reduction due to increased plant life
Percentage of Total Savings
5
2
2
45
22
4
20
3
Identify a well defined tribological problem either from your work experience or from your
everyday life and then list all the individual scientific/technical disciplines that have a bearing
on the problem and explain why.
Answer.- Tribology of walking. Friction between shoes and the ground makes possible
the act of walking. As the rubber sole contacts the floor underneath and the foot pushes forward, the frictional force (under normal conditions) resists the displacement and allows firm
placement of the foot that makes possible moving the rest of the body forward. Disciplines
involved in the analysis of the tribology of shoes include solid mechanics, materials science,
chemistry and mathematics.
2