Trade-off between specific flexural rigidity and the relative width of the first absolute bandgap in a periodic lattice sandwich beam
Year: 2026
Type: article
Abstract: Periodic architectured structures can exhibit absolute bandgaps, but widening them at low frequencies is often accompanied by a reduction in specific rigidity. This study quantifies this trade-off for a thin structure with periodic stiffness contrast, consisting of plates connected at their four corners by X-shaped beam assemblies ( X-beam plate , XBP). It then analyses how this trade-off evolves when two XBP structures are used as the skins of a lattice-core sandwich structure ( X-beam sandwich , XBS). A dynamic-stiffness plate–beam model is validated against a shell–beam finite-element model and then used to explore the geometric parameter space. Performance is assessed using the relative width of the first continuous absolute bandgap and the effective specific flexural rigidity identified from the long-wavelength flexural branch. The results show that widening the XBP bandgap causes a pronounced loss of rigidity. The lattice core does not eliminate this trade-off, but shifts it towards substantially higher rigidity levels: for a relative bandgap width above 50%, the maximum normalized specific rigidity rises from 8.2% for XBP to 244% for XBS. Numerical and experimental results confirm the predicted dispersion and forced-response trends, while revealing modes localized at the ends of finite structures.
Source: Journal of Sound and Vibration
Language: English
Subfield: Acoustics and Ultrasonics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,190
OpenAlex ID: W7220950277