It is clear that the design of DVA involves suitable choice of the following three parameters -

The design objective is to minimize the maximum tranmissibility

The Transmissibility, may be defined as

(18.1)

where is the amplitude of vibration
and is the amplitude of vibration of the base.

Often, we also use a different performance index known as Relative Transmissibility such that

(18.2)

where indicates the difference in amplitude of vibration of and

The equations of motion of the complete system may be written as

	(18.3a)
	(18.3b)

Let us consider the case of harmonic base excitation. Substituting, ,   and in the above equations of motion, we get

	(18.4a)
	(18.4b)