Metal rubber (MR) is widely used for vibration attenuation and noise reduction in harsh environments. However, the internal nonuniformity of MR leads to a more complex spatial distribution mechanism of energy dissipation, while the corresponding influence mechanism on the dynamic behavior remains unclear. Hence a Discrete Element Method (DEM) numerical model is developed together with a contact energy-conversion model for dissipation to investigate the nonuniformity of wire-to-wire contact turns in MR. An effective DEM-based nonuniformity nonlinear dynamics model (DEM-NND) is proposed to capture the dynamic hysteretic mechanical response across different specimen sizes. The results show pronounced Probability Distribution of Low Energy Dissipation (PDLED) and Probability Distribution of High Energy Dissipation (PDHED) within MR, evidencing strong nonuniformity in both the contact and dissipation fields. Specimen thickness markedly alters the volumetric fractions of PDLED and PDHED, thereby modulating stiffness and energy-dissipation performance. The proposed model agrees well with dynamic loading experiments in terms of hysteresis-loop morphology and dissipation capacity. Experimentally, reducing MR thickness from 15 mm to 5 mm decreased the PDHED volume fraction from 33.89 % to 19.61 %, accompanied by a 35.89 % reduction in the loss factor (η). This study elucidates how nonuniformity governs the macroscopic mechanical performance of MR and provides a theoretical basis and quantitative reference for structural design.
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