Research Projects

In recent years, seismic meta-materials, which are created by placing periodic implants such as trees and concrete piles in soil, have been proposed to shield structures from seismic waves. These meta-materials work by damping acoustic waves within a specified frequency range, thereby creating a frequency gap in their overall acoustic response. Previous works on designing these meta-materials ignored soil material nonlinearity, i.e., strain hardening/softening and hysteretic stress-strain behavior, as well as the geometric nonlinearity resulting from gapping and sliding contact between the soil and the implants. This project aims at understanding the dispersion and band gap nature when weak material nonlinear effects in the periodic medium are taken into account. The proposed work would be conducted using perturbation analysis techniques such as Linstedt-Poincare and method of multiple scales to understand the wave dispersion behaviour of the periodic materials with special focus on wave-wave interactions, dependence of band gap on amplitude of excitation, and tunability of the band gap with the nonlinear material parameters.