# Finite element method

1. May 25, 2017

### fonseh

1. The problem statement, all variables and given/known data
In the third picture , I dont understand the circled part , add up the values in the diagonal .. How to do that ?

I dont understand how to get k13 , k14 , k21 , k22 , k33, k41 and k42 .

2. Relevant equations

3. The attempt at a solution
As we see in the second picture , the k21 and k22 = -20 and 20 respectively , why in the third picture , the k1 and k22 become -20 and 40 ?
Is the solution provided wrong ?

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2. May 26, 2017

### fonseh

I tried add up 20, 40, 100/3, and 40/3 , i get 230/3 , none of the number in the matrix is 230/3!!!!

3. May 27, 2017

### fonseh

Can anyone help ?

4. May 27, 2017

### fonseh

why there's 3 boxes ? Why dont the author directly put it into the matrix as k11 , k12 , k21 , k22 , k33 , k34 , k43 and k44 only ?

5. May 27, 2017

### Ray Vickson

No, I doubt that anyone is willing to help you. In many other threads you have been advised, over and over and over again, not to just post images, but you consistently ignore this advice. Now you see the consequences.

6. May 27, 2017

### fonseh

I already highlighted the part i dont understand . This question is rather long . It's difficult to simplify it and type it out . Sorry for the trouble caused

7. May 27, 2017

### fonseh

I already highlighted the part i dont understand . This question is rather long . It's difficult to simplify it and type it out . Sorry for the trouble caused