Static condensation can be applied in cases where the mass matrix is singular to reduce the problem order while preserving the spectrum. However, the reduced stiffness matrix is usually dense, which is the case here. This problem is probably too small to demonstrate that effect. My browser can't read the compressed data files.
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Click on label to get an explanation. 118970 bytes Matrix Statistics Click on label to get an explanation. 16 min max ave. Top 10 out of 131 nonvoid diagonals.