Find the maximum permissible torque for a shaft of known dimensions

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  • čas přidán 13. 09. 2024
  • This mechanics of materials tutorial goes over how to find the maximum permissible torque for a shaft of know dimensions.
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    Thanks for watching, I hope it helps!

Komentáře • 27

  • @LocPH.
    @LocPH. Před 6 lety +3

    Perfect! Exactly what I needed and very well explained. Thank you!

  • @diddlysquids7878
    @diddlysquids7878 Před 2 lety +1

    Cracking video, cheers!

  • @AnthonyLorenzo-du9zb
    @AnthonyLorenzo-du9zb Před 3 měsíci +1

    Isn't the equation for polar moment of inertia for this problem should be J = pi/4 * (Ro^4-Ri^4) ?

  • @Regnbuesolv
    @Regnbuesolv Před 2 lety +1

    Fantastic, thank you so much :)

  • @TheTugge
    @TheTugge Před 5 lety +2

    Thanks for the explanation. What surprised me that the length of the rod doesn't have any effect for this one. But now when I think about it more, it makes sense. The length only changes how much twist can be in the rod before it brakes. Thank you for opening my eyes :D

    • @Engineer4Free
      @Engineer4Free  Před 5 lety +1

      Yeahhhh cool eh. The longer the member, the greater the angle of twist will be, when all else is the same. You might be interested in checking the other torsion videos I did, they are numbers 14-21 here: engineer4free.com/mechanics-of-materials 👌👌

  • @l0m-dev
    @l0m-dev Před 7 lety +1

    Just watched your vid on c++ spaces and tabs! Can you make an update version maybe? Btw great vid

    • @Engineer4Free
      @Engineer4Free  Před 7 lety

      +ShadowPlayz haha nice what program are you if you're watching both courses? For the next little while I'm just focussing on making new mechanics of materials tutorials!

    • @l0m-dev
      @l0m-dev Před 7 lety +1

      No bro, i just watch your vids because they are educational and very fun to watch :) I hope you start with some more programming tho

    • @Engineer4Free
      @Engineer4Free  Před 7 lety

      That's awesome, good for you!! Keep it up and keep checking back :)

  • @wizardhunts8078
    @wizardhunts8078 Před 2 lety

    why did he do 'to the power of 4' for J?

  • @RETROriginalZA
    @RETROriginalZA Před 3 lety

    is 2,893Nm = 2,89KNm ?

  • @danerobinson1387
    @danerobinson1387 Před 4 lety +2

    Sorry for the late comment, where does one find the allowable shear stress?

  • @anaseljamal7105
    @anaseljamal7105 Před 3 lety +1

    what if the shaft is from 2 irons

    • @Engineer4Free
      @Engineer4Free  Před 3 lety +1

      Hey Anas, then it would be similar to this example, www.engineer4free.com/4/angle-of-twist-due-to-torsion-in-a-shaft-with-varying-cross-section but rather than having J1 and J2, we'd have G1 and G2. Assuming the cross section is the same size and that the 2 sections are not overlapping. Also worth checking out the pure bending of composite materials videos (#29-24) here: engineer4free.com/mechanics-of-materials They're about bending, not torsion, but some concepts are transferrable

    • @anaseljamal7105
      @anaseljamal7105 Před 3 lety +1

      @@Engineer4Free thank you sir 🙏
      U saved my life 😂

  • @user-qm8dz8dn7h
    @user-qm8dz8dn7h Před 3 lety

    Are you sure you want to use the inner radius to earn the Maximum Torque out of this?
    Because when we rearrange the equation for Torque it'll be: T = ( Shear stress * I polar ) / ( distance from center ) while we have already fixed values for each of: Shear stress = 85 Mpa & I polar = 1021017.612 mm^4 . And what we have left is the value of: Distance from the center, and since it is in the denominator we need to decrease it's value as much as possible so the Torque's value rise to it's Max.. .
    and in order to do that is to choose the inner radius of the shaft ( 20 mm ) to obtain our MAXIMUM Torque.. am i right ?

    • @uro7314
      @uro7314 Před 3 lety +1

      i think you are wrong...we are essentially looking for the torque which caused the max shear force...so we put in the c at which the shear force is at it's maximum, and that is the outer dimension (30 mm)
      you may want to refer to the equation before it is rearranged for T to visualise this
      take this with a grain of salt though, I'm just a student, but I'm open for discussion :)

  • @kabbashirley2607
    @kabbashirley2607 Před 3 lety

    Why did you not use J=(π×d4)÷32

    • @muazumuazu7757
      @muazumuazu7757 Před 2 lety

      dont think you need the answer anymore😂 but its because it has an opening

    • @r1-ing
      @r1-ing Před rokem +2

      Because instead of D^4 he used r^4. In the video C1 & C2 are radius. d=2*r. Therefore (2*r)^4= 16r. 16/32 gives the 1/2 you see in the denominator. I was seriously confused too. Had to look that one up so I will post here if others were scratching there head the same way I was.