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Mass and Stiffness Matrix Assembly
Posted Sep 29, 2012, 5:12 p.m. EDT Mesh, Modeling Tools & Definitions, Parameters, Variables, & Functions, Structural Mechanics Version 4.3 0 Replies
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I have been exporting mass and stiffness matrices out of Comsol with the LiveLink to Matlab package.
I can not not seem to find how the matrices are actually assembled, in terms of the degrees of freedom and orientation of the matrices.
When I use matlab's eig function to find the eigen vaues and eigenvectors of the system they are arranged in matlab in a non-intuitive format. They are numerically identical to comsol. If I compare the modes shapes from matlab to the displacement output of an eigenfrequency study in comsol this is what I find.
In matlab it is arranged like this, where rz sifnifies rotation around x axis, dx is displacement in x direction
w1 w2...
node1 rx
node1 ry
node1 rz
node1 dx
node1 dy
node1 dz
node2 rx
and so on,
Any Help would be greatly appreciated,
Joshua
Hello J. Mendoza
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