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Rliability factor in Shaft design

  • 15-03-2009 11:45PM
    #1
    Donall87
    Closed Accounts Posts: 1 ✭


    I was wondering does anyone know a formula for calculating a reliability factor of a shaft with a 75% survival rate. Here some info for 50%, 90%,95%.....99.99%

    Survival rate% Kf
    50%.........1
    90% ...... 0.89
    95% ......... 0.87
    98% ......... 0.84
    99% ........ 0.81
    99.9% ......... 0.75
    99.99% .......... 0.70


Comments

  • #2
    Eoin D
    Closed Accounts Posts: 210 ✭✭Eoin D


    Donall87 wrote: »
    I was wondering does anyone know a formula for calculating a reliability factor of a shaft with a 75% survival rate. Here some info for 50%, 90%,95%.....99.99%

    Survival rate% Kf
    50%.........1
    90% ...... 0.89
    95% ......... 0.87
    98% ......... 0.84
    99% ........ 0.81
    99.9% ......... 0.75
    99.99% .......... 0.70

    Could you not just graph it?

    Suppose it wouldn't be the most accurate seeing as it's in quite a big step


  • #3
    Turbulent Bill
    Registered Users, Registered Users 2, Paid Member Posts: 1,643 ✭✭✭Turbulent Bill


    Eoin D wrote: »
    Could you not just graph it?

    Suppose it wouldn't be the most accurate seeing as it's in quite a big step

    +1, if that's all the info you have then assume the behaviour is continuous, fit a sensible curve through the points and interpolate the 75% value. Note that this will be very sensitive to the accuracy of the 50% value, but I'm guessing this is a college question rather than something real-life.


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