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Description
Reducing vibration transmission through plate junctions is a challenging problem for limiting flanking sound transmission. Conventional approaches rely on structural decoupling or addition of mass, often involving increased structural complexity, material use, and limited low frequency effectiveness. This work explores an alternative, lightweight solution using resonant metamaterials, implemented as a strip of subwavelength resonators along the junction line. Such resonators can introduce bandgaps that inhibit free traveling waves within targeted frequency ranges. To predict vibration transmission through plate junctions treated with a resonant metamaterial strip, a two-step prediction model is proposed. First, wave propagation through junctions between semi-infinite thin plates connected at arbitrary angles is described using a wave-based analytical model. Within this model, multiple wave types are considered, and the metamaterial treatment is included via homogenized effective properties. This allows the computation of frequency dependent reflection and transmission coefficients, accounting for wave conversion between different wave types. Second, these results are used to compute coupling loss factors and are incorporated in a statistical energy analysis model to predict vibrational energy exchange between the connected plates. The proposed framework is experimentally validated on a junction of two aluminum plates connected at different angles, both with and without resonant metamaterial strips. Different strip widths are considered. Predicted velocity level differences agree well with those obtained from the measurements, showing reduced vibration transmission near the local resonance frequency.