Determination of signal processing methods in vibration analysis of antivibration rubbers and calculation of possible dynamic properties by transfer function

With the increasing prevalence of electric vehicles, vibration testing of elastomer based antivibration products at higher frequencies has become significantly more important. In this thesis, sinusoidal sweep vibration tests were conducted on rubber bushing and rubber spring specimens within the 200 Hertz–3000 Hertz frequency range. Each test condition was repeated four times using four different sampling rates (8192, 16384, 32768, 65536 Hertz). The acceleration and force data obtained from the tests were analyzed using Matlab via the Welch method. Through this analysis, APSD (Auto Power Spectral Density) and CPSD (Cross Power Spectral Density) were calculated. Subsequently, mechanical dynamic properties such as coherence, transfer function [dB], dynamic stiffness, storage stiffness, loss stiffness, phase, tan delta, damping coefficient, and transmissibility were derived. Additionally, four different transfer function methods were applied, and the results were compared across the different sampling rates. The thesis also elaborates on the types of sensors used in vibration testing, the different vibration testing devices available, and the rationale behind selecting the specific equipment employed in this study. As the market share and popularity of electric vehicles continue to grow, the exposure of elastomer antivibration components to higher frequency vibration conditions necessitates studies like this. The primary contribution of this study to literature is the provision of a highly sensitive dataset that examines the dynamic behavior of rubber materials under high-frequency conditions. By offering original findings applicable to industrial practices, this work aims to guide the future development of design and testing standards for antivibration products.