What size is the Global Stiffness Matrix in this Example?

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SUMMARY

The global stiffness matrix for a beam composed of three elements and four nodes is indeed an 8x8 matrix, calculated based on the number of nodes multiplied by the degrees of freedom per node. This method is consistent with the calculation of a 6x6 stiffness matrix for a beam with two elements and three nodes. The discussion highlights the lack of straightforward resources that clearly explain the methodology without shortcuts or obscured details.

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TL;DR
4 nodes global stifness matrix
does this Beam, composed of three elements and 4 nodes(considering lateral deflections and slopes) has an 8x8 global stifness matrix
and if so is the global matrix calculated the same way as a 6x6 stifness matrix for the same kind of beam but only with two elements and 3 nodes
 

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The size of global stiffness matrix is the number of nodes multiplied by the number of degrees of freedom per node.
 
Arjan82 said:
There is tons of info on the web about this:

https://www.google.com/search?q=global+stiffness+matrix
Yes, all bad. I looked at many sources and none of them follow a straightforward problem without shortcuts that obscure the method or missing key details or not explaining where things go or mixing numbers and matrices or whatever.
 

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