FFT Applications
FFT Vibration analysis
V-1-1 Measuring natural vibration frequency and damping ratio by hammering test

- This example shows how to measure natural vibration frequency and damping ratio etc. Suspend a measurement object in a free vibration (or place it on something soft) and perform hammering test by the GK-3100 Impulse hammer. And then detect the free damping vibration by an accelerometer. The DS-5000 series calculates the frequency response function of acceleration (A) and hitting force (F) by applying them to the following calculation, and obtains the resonant frequency at the peak of (A) / (F). (In this example, the peak value of (A)/(F) equals to the resonant frequency, natural vibration.)
- Frequency response function = Acceleration (A) / Hitting force by the GK-3100 (F) (Accelerance < Inertance >)
- You can see several peak values depending on a shape of a measurement object. Damping ratio also can be calculated by using half-power bandwidth method. sMoreover, integrating function of the DS-5000 series enables display and evaluation of velocity/power (mobility), displacement/force (compliance), force/acceleration (dynamic mass), force/velocity (mechanical impedance) or force/displacement (dynamic rigidity).
Product list
Model | Product name | Remarks | Qty | |||
---|---|---|---|---|---|---|
1 | DS-5000 O-Solution | 3ch 40 kHz FFT set |
DS-5100 Main Unit DS-0523 3ch 40 kHz Input Unit OS-5100 Platform OS-0522 FFT Analysis Function OS-0512 Hardware Connecting Function |
1 | ||
2 | GK-3100 | Impulse force hammer | Frequency range:: up to 8 kHz, resonance frequency: 31 kHz, hammer cable (3 m) & signal output cable (0.9 m) (included) | 1 | ||
3 | NP-3412 | Accelerometer with built-in preamplifier | Ultra compact, lightweight (0.5 g), frequency range: 0.3 Hz to 20 kHz ±3dB, signal cable (3 m) (included) | 1 | ||
4 | NP-0151A | Signal cable 1.5 m | Compatible Sensor Models:NP-2910/NP-3110/NP-3412/NP-3414/NP-3418 Cable diameter : φ1.2 mm Type : Low noise cable |
1 | ||
5 | NP-0021 | Miniature / BNC Conversion Adapter | NP-0153A Converts the NP-0153 signal cable terminal to BNC connector and input to the DS-5000 series BNC connector. | 1 | ||
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