Matrix operations failing.

[reignofratch]

I am having multiple issues with matrix operations in an FEA assignment.

The first was multiplying a transformation matrix by a stiffness matrix, I got an error stating the units were incompatible.

Removing the units from everything solved this.

The second was an error with integrating inside a matrix. It said nothing was defined and I couldnt redefine any variables. It was like they were stuck with the origional variables. to solve this, I did the integration by hand instead.

Now I cannot get the local forces to transform into global.

I am unable to attach the file because this website says the contents of the attachment do not match its file type.

I will attach a screenshot instead.

Thanks in advance.

[LucMeekes]

There still is a serious bug with this web site.

To attach a sheet file you best zip the prime sheet file: use windows explorer, select the file, right-mouse click and select 'send to' a 'compressed (.zip) folder'.

You can attach the .zip file with no problems.

Success!
Luc

[LucMeekes]

And to answer your first question:

Success!
Luc

[LucMeekes]

And here's an example of integrals as matrix elements:

[reignofratch]

Thanks a ton!
My units issue was definitely because of the unit less 0's in the equation.
And the integration issue I solved by integrating outside the matrix and the plugging that value in.
But I did learn a bit from that graphic too!