前言所研究的直升飞机构件疲劳试验系统与标准的材料疲劳试验系统在结构上有很大不同,后者可以较准确地按集中参数建立数学模型,进行分析和综合设计,而前者由于结构的质量和刚度分散度很大,呈分布参数状态。对这类系统,难以准确地建立其数学模型,为此,应用动态测试与识别技术是十分必要的。但是,传统的频率特性测试方法 Preface The fatigue test system of helicopter components studied is quite different in structure from the standard material fatigue test system. The latter can be more accurately set up mathematical models for centralized parameters, analysis and comprehensive design, while the former due to structural Dispersion of quality and stiffness is large, showing the distribution of parameters. For such systems, it is difficult to accurately establish its mathematical model, therefore, the application of dynamic testing and identification technology is very necessary. However, the traditional frequency characteristic test method