Damping Input for the the frequency response analysis
Damping Input for the the frequency response analysis
(OP)
Some time back I was working on the Automotive Exhaust system frequency response analysis. I had been asked to use only the structural damping ratio rather than the viscous damping ratio. Can any one explain why? Is that to simplify the problem or the viscous damping effects are minimal?
Thanks.
San.
Thanks.
San.





RE: Damping Input for the the frequency response analysis
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Damping Input for the the frequency response analysis
Thanks.
RE: Damping Input for the the frequency response analysis
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Damping Input for the the frequency response analysis
Hence it's customory and a reason to use viscous damping model in FEM calculations assuming it has a Rayleigh's proportional damping model.
Regards
RE: Damping Input for the the frequency response analysis
To consider only the structural damping, it's requird to find other damping model values. i.e structural damping = overall damping value - (material damping values+ etc)
But, depending on your structure and type of application, type of energy dissipation, we can make some assumptions.
But generally, material damping contribution is very less compared to structural damping.
2nd case:
If the energy loss in your structure is mainly due to energy loss at joints, rubbing then we can neglect the first term in our Rayleigh damping model. i.e C=bK ( representing purely the energy loss at joints etc)
RE: Damping Input for the the frequency response analysis
Thanks and Regards.
RE: Damping Input for the the frequency response analysis
RE: Damping Input for the the frequency response analysis