The principal disadvantage of the mobility analogy is that it does not maintain the analogy between electrical and mechanical impedance.
12.
The mechanical impedance is a function of the frequency \ omega of the applied force and can vary greatly over frequency.
13.
Wegel, in 1921, was the first to express these equations in terms of mechanical impedance as well as electrical impedance.
14.
The translational impedance analogy describes mechanical systems moving in a single linear dimension and gives rise to the idea of mechanical impedance.
15.
Due to their low modulus, the mechanical impedance of the actuators, they are well-matched to common optical membrane materials.
16.
Electrical impedance is the ratio of voltage and current, so by analogy, mechanical impedance is the ratio of force and velocity.
17.
On the other hand, the impedance analogy preserves the analogy between electrical impedance and mechanical impedance whereas the mobility analogy does not.
18.
Mechanical impedance is represented as an electrical admittance and a mechanical resistance is represented as an electrical conductance in the electrical equivalent circuit.
19.
The unit of mechanical impedance is the mechanical ohm; in SI units this is N-s / m, or Kg / s.
20.
At resonance frequencies, the mechanical impedance will be lower, meaning less force is needed to cause a structure to move at a given velocity.
