一、引言线性结构系统的频率响应函数(FRF)是系统动态特性的描述。频率响应函数可以通过激振—响应试验测得。它在试验模态分析、振动控制以及故障诊断等领域有着广泛的应用。试验模态分析在检验和优化有限元数学模型,在试验/理论联合建模和结构动态设计中都有着重要的应用。而对于试验模态分析中承前继后的重要环节—频率响应测试的精度提出了越来越高的要求。影响频率响应测试精度的主要因素是统计误差,又称方差(Variance)误差,和偏度 I. INTRODUCTION The frequency response function (FRF) of a linear structure system is a description of the system dynamics. Frequency response function can be measured by excitation-response test. It has a wide range of applications in the fields of experimental modal analysis, vibration control and fault diagnosis. Experimental modal analysis plays an important role in the verification and optimization of finite element mathematical models in joint experimental / theoretical modeling and structural dynamic design. For the test modal analysis inherited the important part - the frequency response test accuracy put forward higher and higher requirements. The main factor affecting the accuracy of frequency response test is statistical error, also known as Variance error, and skewness