Final Report: Design of adaptive load mitigating materials using nonlinear stress wave tailoring
Technical Report,17 Sep 2009,16 Sep 2015
University of Illinois - Urbana Champaign United States
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This six-year effort focused on i a fundamental understanding of wave propagation of solitary and solitary-like pulses in one- two- and three-dimensional 1D, 2D and 3D ordered granular media, and ii material design, based on these findings, of novel materials with unprecedented impact response properties. Modeling and experimental efforts on wave propagation in 1D, 2D and 3D granular structures were conducted. These were focused on analyzing the dynamic response of granular materials over a range of loading conditions, evaluating scaling laws for force attenuation and energy dissipation, and design using a robust simulation framework optimized granular structures for specific wave management tasks. Novel physical phenomena such as new nonlinear normal modes in dimers, pass bands, stop bands, and breathers in coupled quasi-1D granular chains embedded in an elastic matrix, lateral energy partition in weakly coupled chains, wave motion control through confinement, etc. were discovered. The material design efforts mainly focused on 1D and 2D geometries involving either granular distributions with spatially optimized granule positions for specific wave mitigation or wave deflection applications, and on rank laminate materials forming a continuum specifically designed for wave tailoring. This report provides a summary of both novel physical phenomena and material design performed.