SWAMI, the Stress WAve MItigation MURI, is a Multidisciplinary University Research Initiative at the University of Illinois at Urbana-Champaign and the California Institute of Technology, funded by the U.S. Army Research Office, whose goal is to develop and exploit nonlinear stress wave tailoring to design adaptive load mitigating materials that provide impact protection and improve crashworthiness of components, vehicles, and structures subject to impact loading. The overall strategy is to control the microstructure of inhomogeneous material systems that encase critical components, so that if electronic devices, munitions, etc., are dropped or otherwise damaged, a stress wave mitigating casing material would channel resulting stress waves to desired locations and away from sensitive areas most needing protection.

Goals and Objectives

This research aims at developing, studying, and understanding new structured protective systems, primarily based on materials incorporating inhomogeneous granular media, phase transforming ceramics, and novel geopolymers. In the process, we plan to study both theoretically and experimentally scalable nonlinear interactions among different layers and to employ granular media as a basis for a new class of nonlinearly adaptive, discontinuous, highly inhomogeneous materials capable of stress wave tailoring, passive and adaptive energy confinement, and energy redirection in preferential directions within the material compatible with design objectives. This project involves fundamental work to understand both experimentally and analytically the energy transfer and dissipation mechanisms in the new materials, but also focuses on transferring these fundamental concepts to actual material systems with demonstrated stress wave tailoring properties.

Specific objectives include

  • Understanding the role of nonlinear contact phenomena in wave propagation in discretely inhomogeneous systems, and to transfer these fundamental concepts into an actual scalable material system
  • Developing a theoretical/computational framework for designing material systems that exhibit adaptive stress wave mitigation characteristics
  • Demonstrating experimentally the stress wave management characteristics of the conceptual material system designs.