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1-Visitor
January 10, 2012
Solved

Always have problems with given/find

  • January 10, 2012
  • 3 replies
  • 2317 views

I have a sheet dealing with volumes of revolution. The specification for this part is thickness +/- 10% based on weight; so to find the tolerance on the thickness, I have to solve for how much the thickness is reduced when the weight is reduced 10%. Therefore, I first calculated the nominal volume. Now, I want to use a solve block to basically say, "find the thickness subject to the constraint that volume is reduced by 10%". But I can't get it to go.

Also, why doesn't my plot show three nice, sharp lines? Each segment of the tube is defined by a line.

I really appreciate your help. Thanks!

Best answer by Fred_Kohlhepp

Your plot doesn't show sharp lines because you didn't specify x, so Mathcad wants to plot from -10 meters to 10 meters, and the space between points is that large. The solution is to specify x as a range variable.

Your solve block is trying to define functions as constraints--can't do that. But you can constrain a function to a value and find the value of parameter that it requires.

3 replies

23-Emerald I
January 10, 2012

Your plot doesn't show sharp lines because you didn't specify x, so Mathcad wants to plot from -10 meters to 10 meters, and the space between points is that large. The solution is to specify x as a range variable.

Your solve block is trying to define functions as constraints--can't do that. But you can constrain a function to a value and find the value of parameter that it requires.

1-Visitor
January 10, 2012

Elegant and simple. Well done! Thanks!