Abstract: An analysis system, including the functions of signal generation, data acquisition, spectrum analysis etc, is developed using the virtual instrument LabVIEW software,for analyzing the vibration testing data of flange connection structures. With the use of the analysis system, analysis of the vibration testing data for the flange and bolt connection structure is completed for various prestressed bold forces. The spectrum analysis and difference analysis show that the dynamic response of the structure is significantly affected by the nonlinear behavior of the flangebolt connection structure. The nonlinear vibration effect and signal asymmetry can be obviously observed, and strongly depend upon the prestress state of the bolts. In virtue of the frequencyspectrum signals, the looseness of the bolts can be identified and some information can be provided for diagnosis of the connection structures.

Key words: vibration and wave, flangebolt connection, vibration measurement, spectrum analysis, LabVIEW

摘要： 利用虚拟仪器LabVIEW软件，针对法兰连接结构振动测试试验，开发具有信号发生（频率可调的伪随机和正弦）、数据采集、谱分析等数据处理功能的分析系统，完成了法兰螺栓连接结构在不同预紧力下的振动试验。通过对试验数据的谱分析、差量分析表明：法兰螺栓连接结构的非线性特性对结构动态响应影响是显著的，各种非线性振动现象明显，信号不对称性表现的尤其突出，且与螺栓的预紧状态密切相关。借助于频谱信息，可判定螺栓松紧的程度，为结构连接状态的诊断提供依据。

关键词: 振动与波, 法兰连接, 振动测试, 谱分析, LabVIEW