文档介绍：STRUCTURAL TESTING
Part I: Mechanical Mobility Measurements
By
Ole Døssing, Brüel & Kjæ
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Noise and Vibration: Cause and Effect ....................…. 3 Excitation ............................................................................ 26
Signal vs. System Analysis ..........................................…. 5 Implementing the Excitation .......................................... 28
Trouble-shooting ................................................................. 6 Response Measurements ................................................ 30
Treating Dynamic Problems ............................................. 8 Random Excitation ............................................................ 33
Modal Analysis ................................................................... 10 Pseudo-Random Excitation ............................................. 34
Mathematical Dynamic Models ..................................…. 11 Impact Excitation .............................................................. 35
Application of Modal Data ..........................................…. 12 Impact Testing and the Coherence Function ........... 36
Verification of an Analytical Mathematical Model …. 13 Window Techniques for Impact Testing ......................39
The Frequency Response Function ............................. 14 The Transient Window .................................................... 40
Mobility Measurements-Definitions .............................. 16 The Response Window .................................................... 41
Estimation of the FRF ..................................................... parison between Excitation Forms ..................... 42
The Dual Channel FFT Analyzer .................................. 21 Calibration ........................................................................... 43
Errors……………………………………………………………. 23 Case History: Vibrations in a Gantry Crane ............ 45
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