Vibration Category III

• Filters: low pass, band pass, high pass, band stop
• Sampling, aliasing, dynamic range
• Signal-to-noise ratio
• Resolution, Fmax, data collection time
• Averaging: linear, overlap, peak hold, time synchronous
• Windowing and leakage
• Order tracking 
• Cross-channel measurements 
• Correlation and coherence

• Collecting data – ensuring you have the correct setup
• When should you use waveform analysis?
• Diagnosing unbalance, misalignment, bent shaft, eccentricity, cocked bearing, resonance, looseness, and other conditions

• Collecting data
• Bubble diagrams 
• Diagnosing unbalance, misalignment, bent shaft, eccentricity, cocked bearing, resonance, looseness, and other conditions

• Natural frequencies and resonance
• Mass, stiffness, and damping
• SDOF and MDOF

Testing for Natural Frequencies

• Run-up coast down tests
• Bode plots and Nyquist (polar) plots
• Impact and bump tests

• Can we prove the existence of a natural frequency?
• Visualizing vibration 
• Setting up the job
• Collecting phase readings correctly
• Interpreting the deflection shape
• Using Motion Amplification

• How does modal analysis differ from ODS?
• How does Finite Element Analysis (FEA) differ from modal analysis?
• A quick review of the modal testing process

• The effect of mass and stiffness
• Beware of nodal points 
• Adding damping
• A “trial and error” approach
• A “scientific” approach
• Isolation
• Tuned absorbers and tuned mass dampers