Vibration Absorption of Nonlinear Energy Sink for Non-resonant Frequency Band of Rectangular Plate

In this paper, a nonlinear energy sink (NES) is designed to suppress the vibrations of a rectangular plate, where the vibrations within a non-resonant band of the plate are mainly investigated. The selected frequency range is 9–11 Hz with a loading frequency interval of 0.5 Hz. The harmonic excitation experiments with fixed frequency are conducted within the non-resonant band to obtain its amplitude-frequency curves. The results indicate that the NES always has effective vibration absorption with the variations in NES mass and spring stiffness under low excitation accelerations. However, the rectangular plate exhibits a higher branch of response within the low-frequency range under high excitation accelerations. Metrics such as the effective value of response acceleration and the vibration level are introduced to evaluate the experimental results to analyze the vibration absorption of the NES. The study reveals that optimal performance is achieved when a non-weighted NES with a spring having a wire diameter of 1.2 mm and an external diameter of 10 mm is attached to the rectangular plate. This device yields a reduction of vibration level by 7.29 dB.