1. Goals: Develop inexpensive lightweight low-cost structures to safeguard civilian and defense assets against blast loads (thermo-mechanical shocks, high energy directed threats). Identify anticipated threats and devise techniques to mitigate them. Learn socio-economic and other factors (e.g. upbringing, education, job opportunities) that promote persons to engage in life-threatening events. Educate and train personnel in identifying likely threatening events, evacuating people quickly, safely, and providing emergency medical help and counseling. Blast Mitigation Team (BMT) High performance multiscale mathematical and computational modeling of high strain rate, large strain, and elevated temperature phenomena Durability-based design and lifetime assessment of composite materials and structures Design, rapid manufacturing and characterization of structural composite systems Polymer and composite processing R. C. Batra S. W. Case J. J. Lesko S. W. CaseR. C. Moffitt

2. Current Project: Analysis of Injuries in Persons Wearing Soft Body Armor due to Impact Loads Fig. from Roberts et al., JHU APL Tech. Digest (2005) Simulation of a rojectile impacting a soft body armor (Batra et al. (2007)) Model of soft body armor, skin, ribs and soft tissue behind ribs Publication: G. M. Zhang, R. C. Batra and J. Zheng, Effect of Frame Size, Frame Type, and Clamping Pressure on the Ballistic Performance of Soft Body Armor, Composites B (in press, available online).

3. Project recently completed: Blast Resistant Light-Weight Laminated Composites Objectives: Develop a science based tool to optimally design blast resistant marine composites. Approach: Use thermodynamically consistent material and geometric nonlinear theory of internal variables to account for energy dissipated due to different failure mechanisms, and determine optimum values of parameters. Work Completed: Have developed, verified and validated a 3-D FE code to analyze transient finite deformations of a laminated composite structure subjected to explosive loads, and ascertained the effect of material, geometric and damage parameters on energy dissipated. Relevance: The developed mechanics based tool will enable engineers design lightweight blast resistant structures. Validation Publications: Blast Resistance of Unidirectional Fiber Reinforced Composites, Composites B (in press; available on line) Response of Fiber Reinforced Composites to Underwater Explosive LoadsResponse of Fiber Reinforced Composites to Underwater Explosive Loads, Composites B, 38, 448-468, 2007. Modeling Damage Development in Polymeric CompositesModeling Damage Development in Polymeric Composites, Composites B (in press, available on line)