FEA - global stiffness matrix

[Teddy]

Good day. I was wondering if anyone can introduce a good tutorial and help me on how I can compile the global stiffness of this example problem in mathcad prime. I am currently studying FEA Method and still do not know how to properly mesh 2d into a single matrix. I hope anyone can help me program it. Thank you.

[rgunwaldsen]

Perhas this link will help.

https://www.youtube.com/watch?v=D6Qdy929K0Q 

[ChrisKaswer]

If you happen to have access to Mathcad v15 and you have the mechanical engineering e-books, there is a book about FEA - "Finite Elements Beginnings". All the examples you will need are contained in that book.

[terryhendicott]

Here is one way

But it is not giving the correct answer so looking at it

[terryhendicott]

Hi Teddy,

Happy it is now working with a third attempt at elemental stiffness matrix.

[terryhendicott · Accepted solution]

Hi Teddy

Errata for reference https://sharif.edu/~ghaemian/Finite-Element_files/File/chapter3.pdf that gives erroneous results.

Make three small changes and it works

1> Add minus to k2 in column 0

2> Add minus to k5 in column 0

3> For k3 first term divisor is S not 3.

Cheers

Terry