Damping Ratio Estimation of Linear and Non-Linear Viscoelastic Materials Using Hilbert and Wavelet Analysis Techniques

The damping property is a material's energy dissipation capacity, indicating its ability to resist vibrations. The parameters of damping characteristics can be evaluated using the traditional Fast Fourier Transformation (FFT) technique, which suffers from the loss of time. Therefore, Hilbert Transform (HT) and Wavelet Transform (WT) have been developed to overcome such problems and help comprehend damping properties precisely with time and frequency. This study evaluates and compares damping ratio assessment using HT, WT, and Log Decrement in linear and non-linear viscoelastic material models. To test the adapted HT and WT methods, we developed a homemade MATLAB code to evaluate the damping ratio of two data sets. Analytical data obtained from solving a linear viscoelastic material model and numerical data attained from the FE-model of a non-linear viscoelastic material were both subjected to vibration. The error percentages of the damping ratio estimated by HT and WT were 6.1 and 11.75, respectively, compared to 43 for Log Decrement. These results confirm that HT and WT can accurately predict the damping ratio of non-linear viscoelastic material models.