Dynamic tests of a shock absorber based on elastomer with ferromagnetic micron-sized powder filler

Purpose. Experimental study of the vibration characteristics of a passive damper using an elastomer with ferromagnetic powder filler as a working body. Methods. Measurement of amplitude-frequency characteristics of a uniaxial damper on a vibration test bench in a wide range of frequencies of harmonic action. Laboratory tests of the damper were performed in the loaded and unloaded conditions, varying the simulated payload from 0 to 600 g in 200 g increments. Results. Uniaxial dampers of the original design of Stepanov G.V., consisting of two cylindrical magnetizable elastomers located between three ring permanent magnets facing each other with same poles, were manufactured. The elastic elements are placed inside an assembled supporting housings equipped with flanges for bolting to the vibration test platform. The housings were made of plastic by 3D printing. In a wide range of vibration loads the influence of the magnetic field on the vibration-protective characteristics of the damper by replacing permanent magnets with nonmagnetic washers was investigated. The amplitude-frequency characteristics of the dampers are typical for similar industrial products with a small bandwidth in the lower frequency region and a resonance peak after which the transfer function monotonically decreases. The measured characteristics demonstrate that the presence of permanent magnets in the damper design leads to a significant reduction of the transmission coefficient at the resonant frequency while increasing the bandwidth. Conclusion. Elastomers with powder ferromagnetic filler are promising materials for manufacturing dampers of new designs. The use of magnetic interaction forces of filler particles in the polymer matrix enhances dissipative properties of the damper, which reduces the response of the system at its own resonant frequency, which demonstrates the prospects of their application for the protection of electronic devices under vibration loads.