5% Critical Damping
5% Critical Damping
(OP)
Can someone explain, in laymans terms, what 5% critical damping means; as it applies to Seismic Design Values (Spectral Values, Ss and S1).
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RE: 5% Critical Damping
RE: 5% Critical Damping
RE: 5% Critical Damping
RE: 5% Critical Damping
RE: 5% Critical Damping
It is an example of codified engineering judgement. I was fortunate enough to attend a lecture by the famous Prof. Tom Paulay where he openly admitted that the 0.6 term many codes still have in the base shear formula was added because the loads calculated when they first came up with the process for modern seismic design simply seemed too high...
So they just reduced them. *smiles*
The reality is that if the system is well designed with inherent ductility the the right places and over designed in areas of criticality, by which I mean a proper Capacity Design solution like we only rarely see in North America, the actual input load is much less meaningful than the system behaviour. That's pretty fortunate too, as I have yet to see any seismic record that looks like a code model loading! Lol....