An Ultra-Low Frequency Two DOFs’ Vibration Isolator Using Positive and Negative Stiffness in Parallel

Table 1

Simulation parameters of vertical direction.

Parameters	Name	Values
	The mass of payload	1000 kg
	The effective sectional area of the air chamber	0.0343 m^2
	The initial volume of the air chamber	0.002 m^3
	The adiabatic coefficient	1.402
	The pressure of atmosphere	101.325 kpa
	The dimension of the upper/lower magnets (length)	0.035 m
	The dimension of the upper/lower magnets (width)	0.014 m
	The dimension of the upper/lower magnets (height)	0.007 m
	The dimension of the middle magnet (length)	0.030 m
	The dimension of the middle magnet (width)	0.010 m
	The dimension of the middle magnet (height)	0.010 m
	The distance between the magnets	0.012 m
	The positive stiffness of vertical direction	3.09e5 N/m
	The negative stiffness of vertical direction	−2.52e5 N/m
	The system stiffness of vertical direction	5.68e4 N/m