Skip to main content
R
Ramakr561-Visitor
1-Visitor
April 6, 2017
Question

Not return Value when using integral in MathCad Prime!!

  • April 6, 2017
  • 2 replies
  • 4137 views

Hi Every one

Can any body Help me about this problem?

I Have Attached main file which is done by MathCad Prime 4.0

This is distributed load on a simple support beam and "V" and "M" are shear and moment, regardless of what is physical meaning of this parameters just as a mathematics

I do not know why M(x) does not return any answer while I can take answer in MathCAD 15  with same formulas!!

I do not want to use Evaluate for first integral because it makes another problem when "a=0"

Thanks in Advance

Ramak

Question.pngjavascript:;Question-15.png

2 replies

W
Werner_E25-Diamond I
25-Diamond I
April 7, 2017

Simply add the unit to the lower integral limit 0.

Instead of "0 ft" you may also write "Zero" (without the quotes and note the capital "Z").

For some reason its not necessary to do so for the second integral, but it sure is good habit to do.

Also its not necessary to write xi (or anything other than x) but its the correct mathematical way to do. You should not name the upper limit the same as the variable of integration.

    R
    Ramakr561-VisitorAuthor
    1-Visitor
    April 7, 2017

    Wow...

    Thanks a lot

    I never thought I should mention unit beside 0

    Now it is working and I can Continue

    But i did not understand why should I use some variation except x...

    Thanks a million

    W
    Werner_E25-Diamond I
    25-Diamond I
    April 7, 2017

    > But i did not understand why should I use some variation except x...

    Because x as upper limit of the definite integral and xi as variable of integration are two completely different things and therefore should be named differently. Its not mandatory to do so in Mathcad. Mathcad correctly interprets what you mean and first uses x as independent variable in the integration and then as specific upper limit of the integral which then gets the independent variable for the function you assign the integral to.

    -
    -MFra-21-Topaz II
    21-Topaz II
    April 7, 2017

    You could also follow this "road" ...:

    Simple support beam.jpg

      R
      Ramakr561-VisitorAuthor
      1-Visitor
      April 7, 2017

      Thanks a lot

      it is another choice and every root has its own benefits

      may I ask you how can I find and learn about forms of evaluation, I mean the terms of "Simplify" and "Max" you use at the to of evaluate  icon??

      Thanks

      W
      Werner_E25-Diamond I
      25-Diamond I
      April 7, 2017

      But keep in mind that symbolic evaluations in Mathcad are very weak and cannot be compared to those of Maple or Mathematica (not even Matlab, which basically uses the same engine). If your function W(x) gets more complex or if you use if-statements or if-functions instead of the Heaviside function the symbolics will fail. On the other hand - if possible its a good idea to symbolically evaluate the integral(s) as the numerical calculation of those double integrals takes a lot of time and things can be speeded up that way.

        Terms & ConditionsAccessibility statement