一引言机械系统的振动是个复杂的波形,某种程度上这个波形反映机械各部分正常工作状态下动力场的响应。最初,机械某部分的响应由衰减量和实际力传输通路的刚度、动力场大小和出现故障严重程度等所决定。对于一组处于类似的加载和工作环境的机器,希望激振和信号衰减特性都近似地相同,因此,可通过对应的振动历程分析比较而推断出机内另件的相对状 I. INTRODUCTION Vibration of a mechanical system is a complex waveform. To some extent, this waveform reflects the response of a dynamic field in normal operation of various parts of the machine. Initially, the response of a part of a machine is determined by the amount of attenuation and the stiffness of the actual force transmission path, the size of the dynamic field and the severity of the failure. For a group of machines in a similar loading and working environment, it is desirable that both the excitation and the signal attenuation characteristics be approximately the same, and therefore the relative shape of the internals in the machine can be inferred by analyzing and comparing the corresponding vibrational history