What is band width in finite element analysis?

Question

Structural dyanamics,rotor dynamics

Answer 1

Bandwidth relates to the matrix that is created when the computer program sovles the problem. Whenever you run an FEA simulation, the geometry paramters and the boundary conditions get transformed into matrices that the computer uses to solve the problem.It is the size of these matrices that determine how long it takes to run the simulation (a larger more complex problem requires larger matrices). However, in order to optimize computing time you want a matrix that has values along the diagonal and zeroes everywhere else. This can be accomplished by carefully organizing nodes in the FEA model. The bandwidth is how wide the diagonal of non-zero values is. So for example

Bandwidth of 2

1 1 0 0 0
0 1 1 0 0
0 0 1 1 0
0 0 0 1 1

The larger the bandwidth the longer it takes the computer to solve. In reality these matrices can be 100's x 100's in size.

Answer 2

As far as I am able to guess, bandwidth would imply a frequency band for vibration analysis. For example, if a structure resonated strongly between 800 and 1200 Hz, you could say it had a strong response in this bandwidth.

Or it could be referring to something else. I'm not entirely sure.