用敲击法识别位移模态和应变模态

本文提出了在振动模态试验中用电阻应变片直接识别位移模态和应变模态的理论和方法,提出应变导纳概念,建立了应变和振动位移的关系,推导出在振动系统中用应变量表示的传递函数公式。用本方法可以识别出系统的模态参数(包括应变模态、应力模态)。

STUDY ON DIRECT IDENTIFICATION OF DISPLACEMENT MODE AND STRAIN MODE BY IMPULSE EXCITATION

The theory and method of direct identification of displacement and strain modes for vibration modal test with strain guages are described. The concept of strain mobility, strain displacement relationships and derivation of formulae of transfer functions in terms of strains are considered. The system modalparameters, including the strain mode and stress mode etc., can be identified by the present method. This is a new development for modal tests of impules excitation.