Mechanical Property Degradation of Entangled Metallic Wire Materials under Vibration Environment: Experiments and Prediction Models

Entangled metallic wire material (EMWM) can be utilized as a novel elastic element in vibration isolation devices for mechanical actuators. This paper presents a vibration experiment aimed at investigating the degradation behavior of mechanical performance in EMWM under a cyclic compressive environment. An electric vibration testing system, coupled with an isolation structure, is employed to apply compressive loads to the EMWM specimens. Through visual observations and quasi-static compression tests, the variations in geometric morphology and mechanical properties are studied, considering different relative densities and vibrational stress amplitudes. The results indicate a significant reduction in the compressed dimension of the specimens as the number of cycles increases, without any wire fractures or wear. The mechanical properties exhibit an increasing secant modulus and a decreasing loss factor. These variations ultimately lead to a gradual deviation of the vibration characteristics of the isolation structure from its design state, including resonance frequency and transmission rate. To forecast the mechanical property degradation of EMWM, prediction models are proposed, incorporating its dimensions, modulus, and damping by fitting the experiment results. This research provides valuable experimental data and presents an effective method to determine the operational lifespan of vibration isolators utilizing EMWM.