Materials in Extreme Dynamic Environments Collaborative Research Alliance

Materials in Extreme Dynamic Environments (MEDE) Collaborative Research Alliance was a research program initiated and sponsored by the US Army Research Laboratory. The objective of the program was “to establish the capability to design materials for use in specific dynamic environments, especially high strain-rate applications.”^[1]

Collaborative Technology and Research Alliances is a term for partnerships between Army laboratories and centers, private industry and academia for performing research and technology development intended to benefit the US Army. The partnerships are funded by the US Army.^[2]

History

Since approximately 1992, ARL formed a number of partnerships that involved the triad of industry, academia and government. One of them was the Materials in Extreme Dynamic Environments (MEDE) Collaborative Research Alliance which was awarded in 2012. The program will be completed in 2021.^[3]

Objectives

The objective of the MEDE program is to develop technical and workforce capability to design, create and optimize novel material systems that exhibit revolutionary performance in extreme dynamic environments. Research activities in MEDE are focused on a materials-by-design process involving a canonical model and a mechanism-based strategy. Multiscale and multidisciplinary modeling capabilities were used to predict material structure, properties and performance.^[4]

Research thrusts

The MEDE program was organized around research thrusts in four material classes (ceramics, composites, metals and polymers) which included the following:^[5]

• Advanced Experimental Techniques: developing experimental methodologies to interrogate and characterize the in-situ materials response to extreme dynamic environments at critical length and time scales.
• Modeling and Simulation: developing computation approaches to predict the materials response to extreme dynamic environments at critical length and time scales.
• Bridging the Scales: developing physical and mathematical constructs necessary to bridge critical length and time scales.
• Material Characteristics and Properties at Multiple Scales: utilize existing and novel experimental methodologies to identify the comprehensive set of material characteristics, microstructural features, and dynamic properties that govern high rate deformation and failure phenomena, and to validate computation approaches in order to bridge the characteristics length and time scales.
• Synthesis and Processing: incorporate research discoveries to enable the syntheses of novel materials and the processing of final products with critical material characteristics and resulting properties.

Participants

The research under this program was performed collaboratively by scientists of the US Army Research Laboratory and by scientists and engineers of the following institutions:^[6]

• Johns Hopkins University
• California Institute of Technology
• Rutgers University
• University of Delaware
• Drexel University
• Ernst Mach Institute
• Morgan State University
• New Mexico Institute for Mining and Technology
• North Carolina Agriculture and Technical State University
• Purdue University
• Southwest Research Institute
• University of North Carolina at Charlotte
• University of Texas at San Antonio
• Washington State University

Results

Examples of research results developed by the MEDE program include the following:^[7]

• Mitigation of amorphization in boron carbide through silicon doping.
• In situ visualization of fracture in boron carbide using high-speed x-ray phase contrast imaging (XPCI).
• A materials-by-design framework for glass-epoxy composite interphases using molecular dynamics simulations.
• A modeling framework to predict the evolution of dynamic micro-mechanical damage mechanisms and their interactions as a function of the constituent. properties of the fiber, matrix and interphase.
• Micromechanical finite element modeling of tensile failure of unidirectional composites.
• Proliferation of twinning in hexagonal close-packed metals (magnesium).
• Understanding the microstructural evolution of magnesium through in-situ neutron diffraction.
• Correlations between fiber morphology and tensile properties in ultra-high molecular weight polyethylene fiber production.
• A sampling-based framework for performing uncertainty quantification and/or probabilistic modeling of materials in armor applications.

References