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## Fast Global Stiffness Matrix Assembly

version 1.0.1 (1.21 KB) by Ayad Al-Rumaithi

Generates global stiffness matrix from elements stiffness matrices in a fast way

Updated 04 Apr 2020

function K=Fast_Matrix_Assembly(Elements)

Input:
---------
Elements: a structure contains Elements{i}.K and Elements{i}.DOFs (Stiffness and Degrees of freedoms of the ith element).

output:
---------
K: Sparse global stiffness matrix

References
-----------------
Cuvelier, François, Caroline Japhet, and Gilles Scarella. "An efficient way to perform the assembly of finite element matrices in Matlab and Octave." arXiv preprint arXiv:1305.3122 (2013).

### Cite As

Ayad Al-Rumaithi (2020). Fast Global Stiffness Matrix Assembly (https://www.mathworks.com/matlabcentral/fileexchange/70447-fast-global-stiffness-matrix-assembly), MATLAB Central File Exchange. Retrieved .

Marius Mellmann

### Marius Mellmann (view profile)

Dear Anilcan Taner,
Elements{i}.K should be the stiffness matrix of ith element .Elements{i}.DOFs degrees of freedom vector of the ith element.
in your example it could be:
Elements{1}.K=KK{1};
Elements{1}.DOFs=[5 1 6];
Elements{2}.K=KK{2};
Elements{2}.DOFs=[6 1 2];
.....
K=Fast_Matrix_Assembly(Elements)

Anilcan Taner

### Anilcan Taner (view profile)

I am having problem with inputs for example;

i have 3x3 matrices named as KK{i} which i=1:9

but I am a bit lost with putting it to the code

Mathew Da Silva

### Mathew Da Silva (view profile)

Are you able to give an example of an input? I am trying to run this for a 3D frame model. Thanks in advance

Yes. It can be used with any type of elements

Nuttibase Charupeng

### Nuttibase Charupeng (view profile)

can this be used for 3-D elements?

Thank you

Nuttibase Charupeng

### Nuttibase Charupeng (view profile)

Very useful. Very fast