Vince provided a link to a paper dealing with the grip topic for tennis rackets, but it is not so easy to get the full paper. I could do that from HAL Science web site but the access to the paper does not work every time. I saved a copy on my PC if one is interested.
Just in case you want to have a go:
https://hal.science/hal-01440222/document
The conclusions of that paper do not appear consistent at first sight, just because the reference taken is the free-free mode of a racket, not the clamped free one which is more practical when one considers a flyrod. The authors refer to a rather fast mode (free-free), undamped, and do not vary conditions up to the point where the rod is fully clamped, undamped again. Bad luck since it is likely that there can be a kind of optimum grip, neither fully clamped, neither fully free, providing the possibility to nearly critically damp a rod. Another drawback is the lack of damping factor values in the paper, so we do not know how critical damping factors were in that study.
I tested a body interface for my SDM model (torsional spring with damper) and even if I can mimic a rebound/hump, this had no effect on the rod itself. I had to introduce a damping function for the rod to mimic a critical damping for the rod, which incidentally influenced the rebound shape.
The internal damping of rods is just very small, Noel did a test by 2007 and calculated a value for the damping factor of a graphite rod, but I cannot find it in my paper files. Orvis produced the Trident series years ago, which had increased internal damping, without great success. I talked about such possibility with a research center of a WW Automotive company, and the conclusion was that one would double the weight of a rod with a system hidden into the handle. The only mean is just the caster himself, and it is not yet clear to me which methodologies are in use among the casting community.
Merlin
