Vibration Damping of Thin-Walled Metal Sheets Using Paint Coatings

Abstract

In this study, the effect of three types of paint coatings, zinc, white camouflage SPR1001, and red rubber, on the vibration damping of thin-walled steel sheets was experimentally evaluated. Dynamic response measurements were performed using a Polytec PDV-100 laser vibrometer with chirp excitation in the frequency range from 1 to 500 Hz. The analysis was carried out in the frequency domain by determining changes in resonant frequencies and vibration amplitudes in the main vibration modes at approximately 65 Hz, 300 Hz, and in the high-frequency range. All tested coatings caused a clear reduction in vibration amplitude in the resonant frequency range. However, the investigated coatings did not act through the same dynamic mechanism. The zinc and red rubber coatings reduced the resonance amplitudes while causing only minor shifts in resonant frequencies, which is consistent with a damping-related mechanism inferred from the observed amplitude reduction. In contrast, the SPR1001 coating produced the strongest amplitude reduction but also a noticeable decrease in the natural frequencies due to its much larger mass increase, indicating a combined damping and mass-loading effect. These results show that thin paint coatings may serve not only as passive damping treatments, but also as a means of tailoring the dynamic response of thin-walled sheet components depending on whether the design priority is amplitude reduction alone or amplitude reduction combined with resonance retuning. To complement the dynamic analysis, additional microhardness measurements of selected paint coatings were performed, allowing a quantitative evaluation of their stiffness and deformation behaviour.