Difference between forced vibration and combined SHM

1. Jan 24, 2008

what is the difference between forced vibration and combined SHM.

since both include motion of particle under the influence of two periodic force

2. Jan 25, 2008

PiratePhysicist

I had to google around for the phrase "combined simple harmonic motion" but from what I see is that combined simple harmonic motion is just a harmonic motion that is composed of two different SHM's. While on the other hand a forced vibration (I'm assuming you're referring to a Force Harmonic Oscillator) is a damped oscillator (damped by neccessity, otherwise you'd have the equations blow up in your face) that is being driven by an outside force.

Basically, forced vibration: there is an outside force acting on it, combined SHM is merely a superpositioning of two motion functions... I may be wrong, but I'm not entirely sure what you mean by combined SHM.

3. Jan 28, 2008

Claude Bile

With SHM, an oscillator always oscillates at its natural frequency.

In the case of a forced oscillator, this is not necessarily the case.

Claude.