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(Solved): A flood-protection dam gate is supposed to operate only once per week for 100 years, but suddenly af ...
A flood-protection dam gate is supposed to operate only once per week for 100 years, but
suddenly after 30 years of use it needs to be operated twice per day (each time the high tide
comes in). Find how much lower the bending stress must be from then on to still give a total
life of 100 years. The material being fatigued is medium-carbon steel (AISI 1040).
Hint
the ultimate strength of AISI 1040 steel is S_(u)=520MPa.
S_(l)=0.9S_(u)
S_(e)10^(6) cycles for bending in carbon steels=0.5S_(u)