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

Abstract

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.

Dynamic Behavior of Viscous Droplets Impact on a Flexible Mesh Surface

“…In addition to considering the inherent properties of the surface and droplet, the presence of vibrations in flexible surfaces introduces a significant level of complexity to the dynamic behavior of droplet impact. − The change of droplet behavior is intricately influenced by surface bending and vibration, thereby converting the kinetic energy of droplet impact into surface vibration energy. Upon impact, the flexible surface undergoes vibrations at a specific frequency and amplitude. − Due to the energy loss caused by vibration, surface energy can be transferred and dissipated, which in turn affects the dynamic behavior after impact. The different frequency vibrations that occur on droplets and surfaces can also cause significant changes in the penetration and stretching behavior of droplets. , …”