The other thing to remember is that it's difficult to damp at low frequencies (needs lots of stuff), so if by bracing you can push the frequencies up, then the damping becomes much easier. On my machine I found that 3mm damping sheet was very effective from about 2....3Khz upwards, but didn't do so much for the fundamental resonance of beams.
Quote Originally Posted by Mud View Post
When you add a brace to a beam, you will tend to split modes into two higher frequency modes (with a node where the brace is attached). When you brace half-way along a beam you will disrupt the first flexural mode, but the second flexural mode will be less effected (the S-shape deflection).
This can be helped by taking care not to have the bracing points at integer sub-multiples of the beam length - i.e. avoid 1/2, 1/3, 1/4.