LAUSR

The application potential of low-frequency forbidden transmission bandgaps (LFTBs) in solid–fluid superlattices (SFSLs) is severely limited, as the angular ranges of LFTBs cannot satisfy diverse practical requirements. To overcome this limitation, 0–3 composites, comprising zero-dimensional solid inclusion powder (labeled as ‘0’) dispersed within a three-dimensional continuous solid matrix (labeled as ‘3’), are adopted as the solid components, to construct the so-called 0–3 SFSL with fluid. Within the Devaney theoretical framework, flexible selection of the solid materials for the ‘0’ and ‘3’, combined with adjustable volume ratios between them, enables tuning of the effective acoustic parameters over a broad range (mass density, longitudinal and transverse wave velocities). Consequently, LFTBs in 0–3 SFSLs can be modulated across an ultra-wide-angle range, even achieving scenarios where the LFTBs are fully closed (omnidirectional transmission) and fully opened (omnidirectional bandgap). Theoretical results based on the transfer matrix method show high consistency with the finite element simulation results. Our work provides the way for SFSLs to meet acoustic insulation application requirements for arbitrary incident angles.