Vibration damping materials and their performance measurement

1. Vibration damping

2. Vibration damping materials

3. Loss Factor

4. Measurement method for vibration damping performance

5. Half-Max Width Method

5-1 Method for determining the loss coefficient from the imaginary part of the frequency response function using the half-width method

5-2 Method for determining the loss coefficient from the real part of the frequency response function using the half-width method

6. Attenuation Rate Method

7. Impedance Method

8.Non-resonant method

9. Standards for vibration damping performance testing methods

10. Testing methods for vibration damping performance

11. Cantilever beam method

11-1 Selection of test specimens

11-2 Example of a cantilever beam block diagram

11-3 Measurement accuracy of loss coefficient in the cantilever beam method

11-4 Precautions for the cantilever beam method

11-5 Selection of equipment to be used in the cantilever beam method

12. Central vibration method

12-1 Features of the Central Vibration Method

12-2 Impedance Head

12-3 Resonance and Anti-resonance in the Central Excitation Method

12-4 Error Factors in the Central Excitation Method

13. Selection between cantilever beam method and central excitation method

14. Comparison of loss coefficients obtained from each test method

15. Mass Cancel

16. The necessity of zoom analysis in FFT

17. Zoom Analysis and Mass Cancellation

18. Measurement of loss coefficients by curve fitting using a polar-zero model

18-1 Introduction

18-2 Extreme Zero Model

18-3 Error function used in curve fitting

18-4 Application to Model Data

18-5 Examples of measurements using this curve fitting method

19. Two-point suspension method

20. Vibration mode dependence of loss coefficient

21. To obtain an accurate frequency response function

21-1 Swept Sun Signal

21-2 Multisine signal

21-3 Composite Impulse

21-4 Random Signals

22. Window function used when measuring the loss coefficient

23. Calculation of Young's modulus, etc.

23-1 Solid wood

23-2 In the case of a two-layer composite panel

23-3 Double-sided composite panel (using the same vibration damping material on both sides)

23-4 Shear modulus and loss coefficient of sandwich-type composite panels (vibration-damping steel plates)

24. Physical Properties of Viscoelastic Materials

24-1 Temperature frequency conversion rule

24-2 WLF equation

25. Conversion Frequency Nomogram

25-1 Creation of a converted frequency nomogram

25-2 Procedure for creating a nomogram

25-3 Points to note when creating a nomogram

25-4 How to read a converted frequency nomogram

26. Inverted U-Plot

27. Approximate formula for the loss coefficient

28. Approximate formula for Young's modulus

29. Measurement of the loss coefficient with respect to strain of vibration-damping alloys

30. References

31. Supplementary Material: "Characteristics of Electromagnetic Exciters (Electromagnetic Detectors) Used in the Cantilever Beam Method"

31-1 Impedance characteristics of electromagnetic detectors

31-2 Measurement of velocity detection response and linearity of electromagnetic detectors

31-3 Excitation force response and linearity of electromagnetic vibrators

31-4 Conclusion