# System vibrations

1. Nov 19, 2008

### wydim

1. The problem statement, all variables and given/known data

a bloc of mass m=175,5 kg is supported by 2 springs K=k/2 = (unknown) and a damper c (unknown). see vibrations.bmp

at 950 RPM, a stroboscope shows that the excentric mass is at his highest and the mass m is at equilibrium position with an upward velocity.
amplitude of the vibrations is 21,5 mm
défault d'équilibrage mo$$\epsilon$$ = 0,18 kg*m

the question is :

natural frequency ? damping factor ? amplitude of vibrations at 1250 RPM

2. Relevant equations

3. The attempt at a solution

I developped the equation of movement

m$$\ddot{x}$$+c$$\dot{x}$$+Kx = mo$$\epsilon$$$$\omega$$2sin($$\omega$$t)

$$\omega$$/$$\omega$$n

#### Attached Files:

• ###### vibrations.bmp
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Last edited: Nov 19, 2008