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joswizz1-Visitor
1-Visitor
April 5, 2018
Solved

Units problems, Concrete shear formula

  • April 5, 2018
  • 13 replies
  • 7799 views

Hi, college student new to Mathcad here. I'm having trouble with the units of a concrete shear formula. I put units to the unit weight correction factor, lambda, but that didn't help.

 

Help would be much appreciated!

Best answer by Werner_E

As Valery already pointed out - look at your definition of lambda - is this really what you intended?

roots.png

BTW, don't post just pictures - its hard to debug a picture. Always post your worksheet as well. You may have to zip it first because a severe bug in this forum often prevents you from uploading the file as it is.

13 replies

V
ValeryOchkov24-Ruby IV
24-Ruby IV
April 5, 2018

Sorry, but what is it

lambda.png

F
Fred_Kohlhepp23-Emerald I
23-Emerald I
April 5, 2018

A very neat work-around for an empirical formula that takes the square root of a stress.

    W
    Werner_E25-Diamond IAnswer
    25-Diamond I
    April 5, 2018

    As Valery already pointed out - look at your definition of lambda - is this really what you intended?

    roots.png

    BTW, don't post just pictures - its hard to debug a picture. Always post your worksheet as well. You may have to zip it first because a severe bug in this forum often prevents you from uploading the file as it is.
      V
      ValeryOchkov24-Ruby IV
      24-Ruby IV
      April 5, 2018

      8.png

      F
      Fred_Kohlhepp23-Emerald I
      23-Emerald I
      April 5, 2018

      Capture1.PNG

      L
      LucMeekes23-Emerald IV
      23-Emerald IV
      April 5, 2018

      Please attach your worksheet. You may have to ZIP it first. A serious bug in this forum often prevents from attaching a mathcad file. In Windows Explorer click with the right-mouse button on the mathcad file and select 'Send to' -> 'Compressed (zipped) folder'. The resulting .zip file can be attached.

       

      Success!
      Luc

      F
      Fred_Kohlhepp23-Emerald I
      23-Emerald I
      April 5, 2018

      My first guess was that you had a unit mis-match,especially after reading Luc's rant about lambda, but you don't.

      Capture.PNG

      Prime is notorious for getting the "labels" wrong.  It's possible (in Prime) to have two things look exactly or nearly the same and be different things; you can have a variable m and it can be six meters long and write m := 6 m.  If the first is labeled "variable" or "-", and the second is "unit" Prime will happily continue.  But if you created something in the red rectangle with one label, and in the rectangle it has a different label, Prime will refuse to continue.

       

      Check that.

        J
        joswizz1-VisitorAuthor
        1-Visitor
        April 5, 2018

        Thank you all for your quick replies. I appreciate it very much!

        S
        SPRstructur15-Moonstone
        15-Moonstone
        April 7, 2018

        if not wrong, You refer this.

        The problem that you can't solve it because shear stress. just put psi   because it from testing and result with square root but it keeping still Stress unit  .
        Hope it useful.

         

        S-1.png

        W
        Werner_E25-Diamond I
        25-Diamond I
        April 7, 2018

        Yes, as Fred already wrote its an interesting workaround to be able to use an empiric formula where f is expected in psi and the square root of it is taken.

        Guess most of us would have done it the "usual" way: remove the unit by dividing by the asked for unit, do the calculation (root) and then add the proper unit.

        Bild.png

        S
        SPRstructur15-Moonstone
        15-Moonstone
        April 7, 2018
        Hi Werner_E
        my purpose I just give simplified to questioner if you have better one for me always accept
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