Skip to main content
P
ptc-47052951-Visitor
1-Visitor
August 28, 2012
Question

Problem with integral

  • August 28, 2012
  • 1 reply
  • 1828 views

Hi,

I have problem with MathCAD Integral. The following are my equations and graph.

Equation.png

According to equation, if xx = 2.9m, the answer is 10kN-m. However, the result is 0.

If anyone know how to solve this issue, please help me to solve this problem.

Thank you.

1 reply

A
AlanStevens19-Tanzanite
19-Tanzanite
August 28, 2012

It's the step changes that the integration routine doesn't like. One workaround is to do the integration piecewise:

Piecewise.PNG

Alan

P
ptc-47052951-VisitorAuthor
1-Visitor
August 29, 2012

Thanks you very for your help Alan. My problem solve.

W
wayne12-Amethyst
12-Amethyst
August 29, 2012

David,Allen is, as is normal, correct.
For more complicated functions, numerical integration with large vertical steps is difficult. You can study the problem by currpting the data a little to replace the vertical line transition with a sloping one. It introduces some error, but on the other hand assuming an infinite slope step is probably not correct either. Anyway for what its worth, see attached.

Terms & ConditionsAccessibility statement