What do the words Resonance and Factor of Separation mean?
These two words are significant only in the context of regular, cyclic loads, as in the case of a hand held electric tool. In this context, when the natural frequency of the part is close enough to the rotational frequency of the motor, then very high amplitudes are encountered. If the structure is designed with added stiffness so that the natural frequency is much higher than the rotational frequency, then the ratio of the natural to the rotational frequency is called the factor of separation. A desirable value of factor of separation is between 2.5 to 3.0.
