I am trying to calculate natural frequency for torsional vibration of fixed fixed beam using following formula in US system.
=1/2*3.142 sqrt(K*g/mr^2) hz
and G=Modulus of rigidity
g=acceleration due to gravity=386.4 in/se2
m=mass hanging on the beam at distance 'r' from the longitudenal axis
My question is how does the equation above (if its right) is affected if I change the beam from fixed fixed to fixed -free.
My guess is it's lower by a factor 2. The mass accelerated is 2x, and the restoring force for a given angular twist is 0.5x so change is √(2/0.5) = 2.
I don't understand m=mass hanging on the beam at distance 'r' from the longitudinal axis.
Just noticed you also posted this in Aerospace.
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