Solved: Re: Problems solving integrals

ptc-5943412 · ‎Apr 25, 2014

Hello,

My name is Tim van Lunteren and I am currently graduating for engineer.

I never used Mathcad before and I just started using it.

I finished some tutorials and practised a bit.

Now I have to make my own equation to calculate the deflection of a thin walled cilindrical beam.

I tried to calculate it manual, but it is just too damn hard and difficult.

I tried to put it into Mathcad. I get the derivatives with respect to the different variables.

I set up three integrals and I want to know the equation to solve it into the three unknown variables.

It just doesn't want to solve and I don't know where to search.

I attached the file. can anyone send me in the right direction?

Greetz,

Tim

Werner_E · ‎Apr 25, 2014

While I personally prefer MC15 over Prime for a multitude of reasons the problem you have is not a Prime or Mathcad question (unless you insist on using the solve block).

Richard has already pointed you to the errors you made and showed how to solve your problem using a symbolically evaluated solve block (thats what Prime won't allow).

You can also use the symbolic solve command (equally in both flavors of the program). See attached a solution in Prime3.

BTW, the error at Rbx is because this variable is not defined and Mathcad therefore would not be able to evaluate that function M() numerically. This error does not affect symbolic manipulations, though.

View solution in original post

Werner_E · ‎Apr 25, 2014

Do you really need a symbolic solution? Then you must use the symbolic "solve".

In contrary to Mathcad 15 and below a solve block (using Find()) cannot be evaluated symbolically.

ptc-5943412 · ‎Apr 25, 2014

Oke, I also have mathcad 15.

I tried it to insert the same into mathcad 15 but it still does not work.

The last equation to solve the matrix does not work:(

Maybe have a solution? (still a newbie)

RichardJ · ‎Apr 25, 2014

In MC15 a solve block must start with the keyword "Given".

You can't leave empty placeholders in equations.

Equations in a solve block require the boolean equals (<CTRL> 😃

There is no Mb, only Ma.

Werner_E · ‎Apr 25, 2014

While I personally prefer MC15 over Prime for a multitude of reasons the problem you have is not a Prime or Mathcad question (unless you insist on using the solve block).

Richard has already pointed you to the errors you made and showed how to solve your problem using a symbolically evaluated solve block (thats what Prime won't allow).

You can also use the symbolic solve command (equally in both flavors of the program). See attached a solution in Prime3.

BTW, the error at Rbx is because this variable is not defined and Mathcad therefore would not be able to evaluate that function M() numerically. This error does not affect symbolic manipulations, though.

ptc-5943412 · ‎Apr 26, 2014

Thank you guys. I understand the program a little bit more and also the end equation seems right.

Greetz