Blast Wave Mitigation in Novel Bio-inspired Inhomogeneous Structures

Engineering structures are prone to blast loads, especially in aerospace, marine and nuclear sectors. Due to the serious need of sufficiently mitigating these loads, this topic is being heavily researched. Interestingly, it is observed that biological structures are inherently designed to deal with extreme load conditions, for example, the beak of a woodpecker. Thus, looking for the solution in nature, wave propagation in various bio-inspired structures have been studied in the recent past, which holds a vast promise for its application in blast mitigation. Of these, various models including sandwich structures, with sinusoidal depth variations, are discussed and investigated in this study. Firstly, finite element modeling is done with the same blast loads and boundary conditions and other viabilities of the shock experiments to obtain the responses. In order to measure the actual response of the structures to blast loadings, a sample is fabricated, experimented and studied in a vertical shock tube facility. Experimental results are also used to validate the finite element analysis results. The study of the propagation of blast wave in these inhomogeneous media having time-dependent material properties in addition to their interaction with the boundaries aids to understand the energy dissipation of the wave fronts. More results for these models are obtained, which gives us more insight into its critical wave propagation characteristics, and for the purpose of overall comparison of the blast mitigation performance. Blast loads of different amplitudes and decay times are considered in order to understand the blast mitigation characteristics of these structures better.