建立了气动隔振系统非线性模型，在此基础上，利用matlab/simulink软件进行了仿真分析，得到了系统
在简谐激励下的响应曲线。结果表明:该系统具有很强的非线性特性,简谐激励会诱发零频偏移，倍/分频现象；频率越接
近系统的线性化固有频率处，零频偏移，倍/分频响应越大。以仿真结果为指导，提出了一种可行的数值解法，在谐波平
衡法的基础上，通过迭代得到求得系统数值解，该法与仿真所得结果吻合性好,从而验证了该数值解法的有效性。

A nonlinear model of pneumatic vibration isolation system was established. Based on this,
simulation analyses were done using matlab/simulink software and the response curves were got under simple
harmonic excitation. The results show that the system has strong nonlinear characters. Simple harmonic excitation
can induce subharmonic/multiple frequency and offset response at the zero frequency. When frequency near to the
linearized natural frequency the subharmonic and multiple frequency become stronger. Guided by the simulation
results, a possible numerical solution was put forward. This solution which based on harmonic balance method got
the numerical solution by using iteration method. The validity of this method is verified through comparisons withsimulation results, which show good agreements with the numerical solution.