Problem description and significance: Light and stiff structures possess high temporal resonance frequencies. However, when coupled to a fluid environment, they radiate sound efficiently! This is because of their low spatial (wavenumber) resonance frequencies, also known as coincidence. This is a challenge for designing quiet passenger cabins in transportation while achieving high stiffness/weight and strength/weight ratios, since quietness demanded by passengers works against higher, stiffer and faster paradigm. Our research in this area relies on the insight of tailoring elastic wave dispersion by using architected materials.

1. Phani, A.S., 2018, Vibroacoustic Response of Lattices: Opportunities and Challenges,  IUTAM Symposium on Architectured Materials Mechanics, September 17-19, 2018 Chicago, IL, USA.
2. Mehr, E.M., and Phani, A.S., 2017, “Sound transmission loss characteristics of sandwich panels with a truss lattice core,” The Journal of the Acoustical Society of America 141, 2921; https://doi.org/10.1121/1.4979934
3. Raghavan, L., and Phani, A.S.,2013,  “Local resonance bandgaps in periodic media: Theory and experiment,” The Journal of the Acoustical Society of America 134, 1950; https://doi.org/10.1121/1.4817894
4. Phani, A.S., Woodhouse, J., Fleck., N.A., 2006,” Wave propagation in two-dimensional periodic lattices,” The Journal of the Acoustical Society of America 119, 1995 (2006); https://doi.org/10.1121/1.2179748

Funding: NSERC Discovery grants program.