Units in a solve matrix inconsistent

Question

Units in a solve matrix inconsistent

drohan (Civil/Environmental)

(OP)

18 Aug 11 16:45

Hello eng-tips forum,

I am new to MathCAD and am having trouble with units in a solve block. Please correct me if I am saying this wrong.

Basically I get results of ft*kip/ft which should really be kip. I am guessing there is some check box to fix this that is buried in one of the options tabs? Please advise!

Thanks in advance,

drohan (Civil/Environmental) · Answer 1 · 2011-08-18 16:49:06

This is the same worksheet saved in an older format just in case.

http://files.engineering.com/getfile.aspx?folder=78b7866f-b6b8-47c7-8ad1-59

IRstuff (Aerospace) · Answer 2 · 2011-08-18 18:45:19

You really can't. The symbolic processor doesn't actually understand units, so the best you could hope for is to replace kip and klf with 1000 lbf and 1000 lbf/ft, and at least, the answer will be in lbf. Since you're only using those two units in the definitions, that shouldn't be a big problem.

However, since you are not actually trying to get a symbolic solution, you can replace the <ctrl>+. with a straight equal sign, which will still do the inline evaluation and give you the numerical answer with kip as the unit. You'll need to assign guess values to Ay, By, and Cy, before the Given.

http://files.engineering.com/getfile.aspx?folder=ffb9d310-97a3-4b5c-8368-57259e47194f&file=test_numerical_only.xmcdz

TTFN

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Units in a solve matrix inconsistent