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eigenfrequency and strenght
Posted 02.06.2010, 09:21 GMT-4 1 Reply
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Hi,
I want to consider the impact of a load strenght on the eigenfrequency of a violin string. But it seams that even if I change it the results are still the same.
Can you help me?
Thanks a lot!
I want to consider the impact of a load strenght on the eigenfrequency of a violin string. But it seams that even if I change it the results are still the same.
Can you help me?
Thanks a lot!
1 Reply Last Post 02.06.2010, 10:04 GMT-4
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Posted:
1 decade ago
Hi Marie
Iassume you are in 3.5 and solid mechanics (?) (it helps to tell the version and application mode for us other out here to better understand what you are doing).
Pls note that if you load your part with a force, this is not taken into account for the eigenfrequency calculations. Often the load induces initial stress, and if the stress strain curve is not fully linear you get non-linear couplings, but as eigenfrqeuency calculations are linearised they will not show anything so long you do not first "pre-stress" your model to set nonzero initial stress.
This is mostly done in two iterations: a) one static to apply the load and calculate the stress, and then b) a restart from this initial condition to linearise an eignefrequency calcualtion there around.
Try "stress stiffening" on the search on the forum (above before the [Go]), there are already a couple of discussion about this
HAve fun Comsoling
Ivar
Iassume you are in 3.5 and solid mechanics (?) (it helps to tell the version and application mode for us other out here to better understand what you are doing).
Pls note that if you load your part with a force, this is not taken into account for the eigenfrequency calculations. Often the load induces initial stress, and if the stress strain curve is not fully linear you get non-linear couplings, but as eigenfrqeuency calculations are linearised they will not show anything so long you do not first "pre-stress" your model to set nonzero initial stress.
This is mostly done in two iterations: a) one static to apply the load and calculate the stress, and then b) a restart from this initial condition to linearise an eignefrequency calcualtion there around.
Try "stress stiffening" on the search on the forum (above before the [Go]), there are already a couple of discussion about this
HAve fun Comsoling
Ivar